The anterior cruciate ligament (ACL) is a band of dense connective tissue which courses from the femur to the tibia. The ACL is a key structure in the knee joint, as it resists anterior tibial translation and rotational loads. When the knee is extended, the ACL has a mean length of 32 mm and a width of 7–12 mm. There are two components of the ACL, the anteromedial bundle (AMB) and the posterolateral bundle (PLB). They are not isometric with the main change being lengthening of the AMB and shortening of the PLB during flexion. The ACL has a microstructure of collagen bundles of multiple types (mostly type I) and a matrix made of a network of proteins, glycoproteins, elastic systems, and glycosaminoglycans with multiple functional interactions. The complex ultrastructural organization and abundant elastic system of the ACL allow it to withstand multiaxial stresses and varying tensile strains. The ACL is innervated by posterior articular branches of the tibial nerve and is vascularized by branches of the middle genicular artery.
The purpose of this study was to verify and characterize the anatomical properties of the anterolateral capsule, with the aim of establishing a more accurate anatomical description of the anterolateral ligament (ALL). Furthermore, microscopic analysis of the tissue was performed to determine whether the ALL can morphologically be classified as ligamentous tissue, as well as reveal any potential functional characteristics.Three different modalities were used to validate the existence of the ALL: magnetic resonance imagining (MRI), anatomical dissection, and histological analysis. Ten fresh-frozen cadaveric knee specimens underwent MRI, followed by anatomical dissection which allowed comparison of MRI to gross anatomy. Nine additional fresh-frozen cadaveric knees (19 total) were dissected for a further anatomical description. Four specimens underwent H&E staining to look at morphological characteristics, and one specimen was analysed using immunohistochemistry to locate peripheral nervous innervation.The ALL was found in all ten knees undergoing MRI and all nineteen knees undergoing anatomical dissection, with MRI being able to predict its corresponding anatomical dissection. The ALL was found to have bone-to-bone attachment points from the lateral femoral epicondyle to the lateral tibia, in addition to a prominent meniscal attachment. Histological sectioning showed ALL morphology to be characteristic of ligamentous tissue, having dense, regularly organized collagenous bundles. Immunohistochemistry revealed a large network of peripheral nervous innervation, indicating a potential proprioceptive role.From this study, the ALL is an independent structure in the anterolateral compartment of the knee and may serve a proprioceptive role in knee mechanics.
A popliteal cyst, originally called Baker’s cyst, is a synovial fluid-filled mass located in the popliteal fossa. The most common synovial popliteal cyst is considered to be a distension of the bursa located beneath the medial head of the gastrocnemius muscle. Usually, in an adult patient, an underlying intra-articular disorder is present. In children, the cyst can be isolated and the knee joint normal. The anatomy, etiopathogenesis, clinical presentation, differential diagnosis, imaging and treatment modalities of the popliteal cyst are presented. The authors try to answer some questions dealing with this condition. Is the cyst isolated, can it be treated as such, is its origin always well-defined and does surgical excision provide a permanent cure?
The functional anatomy of the knee is frequently studied but remains incompletely understood. Numerous authors have described a structure in the lateral knee connecting the lateral femoral condyle with the lateral meniscus and tibial plateau. The goal of this study is to define the incidence, anatomy, and histology of this structure, the anterolateral ligament.The incidence of the ligament was determined in 30 consecutive patients undergoing total knee arthroplasty (TKA) for medial compartment osteoarthritis. The anatomy and histology were evaluated using 10 cadaveric knees.The anterolateral ligament was noted to be present in all 40 knees. In all cases, it was noted to take origin near or on the popliteus tendon insertion and insert into the lateral meniscus and tibial plateau 5 mm distal to the articular surface and posterior to Gerdy’s Tubercle. The average width of the relatively flat structure was 8.2 ± 1.5 mm, and the average length was 34.1 ± 3.4 mm. Histologic analysis revealed a discreet structure with a fibrous core surrounded by synovium. Fibers blended with the popliteus at its origin and with the lateral meniscus as it passed distally.The anterolateral ligament may play a role in preventing anterior tibial translation. The role, if any, of this structure in meniscal stability and the pathology of meniscal tears remain unclear.Not applicable—Descriptive Anatomic Study.
Soccer is the most commonly played sport in the world, with an estimated 265 million active soccer players by 2006. Inherent to this sport is the higher risk of injury to the anterior cruciate ligament (ACL) relative to other sports. ACL injury causes the most time lost from competition in soccer which has influenced a strong research focus to determine the risk factors for injury. This research emphasis has afforded a rapid influx of literature defining potential modifiable and non-modifiable risk factors that increase the risk of injury. The purpose of the current review is to sequence the most recent literature that reports potential mechanisms and risk factors for non-contact ACL injury in soccer players. Most ACL tears in soccer players are non-contact in nature. Common playing situations precluding a non-contact ACL injury include: change of direction or cutting maneuvers combined with deceleration, landing from a jump in or near full extension, and pivoting with knee near full extension and a planted foot. The most common non-contact ACL injury mechanism include a deceleration task with high knee internal extension torque (with or without perturbation) combined with dynamic valgus rotation with the body weight shifted over the injured leg and the plantar surface of the foot fixed flat on the playing surface. Potential extrinsic non-contact ACL injury risk factors include: dry weather and surface, and artificial surface instead of natural grass. Commonly purported intrinsic risk factors include: generalized and specific knee joint laxity, small and narrow intercondylar notch width (ratio of notch width to the diameter and cross sectional area of the ACL), pre-ovulatory phase of menstrual cycle in females not using oral contraceptives, decreased relative (to quadriceps) hamstring strength and recruitment, muscular fatigue by altering neuromuscular control, decreased "core" strength and proprioception, low trunk, hip, and knee flexion angles, and high dorsiflexion of the ankle when performing sport tasks, lateral trunk displacement and hip adduction combined with increased knee abduction moments (dynamic knee valgus), and increased hip internal rotation and tibial external rotation with or without foot pronation. The identified mechanisms and risk factors for non-contact ACL injuries have been mainly studied in female soccer players; thus, further research in male players is warranted. Non-contact ACL injuries in soccer players likely has a multi-factorial etiology. The identification of those athletes at increased risk may be a salient first step before designing and implementing specific pre-season and in-season training programs aimed to modify the identified risk factors and to decrease ACL injury rates. Current evidence indicates that this crucial step to prevent ACL injury is the only option to effectively prevent the sequelae of osteoarthritis associated with this traumatic injury.
The aim of this prospective randomized intervention study was to evaluate the outcome at a 2 and 5 year follow-up whether combined arthroscopic surgery followed by exercise therapy was superior to the same exercise therapy alone when treating non-traumatic, degenerative medial meniscal tears.Ninety-six middle-aged patients with MRI-verified degenerative medial meniscus tear and radiographic osteoarthritis grade ≤1 (Ahlbäck) participated in the study. Radiographic examination was done before randomization and after 5 years. The patients were randomly assigned to either arthroscopic treatment followed by exercise therapy for 2 months or to the same exercise therapy alone. At the start of the study and at the follow-ups at 24 and 60 months the patients answered three questionnaires KOOS, Lysholm Knee Scoring Scale and Tegner Activity Scale and made pain ratings on the Visual Analogue Scale (VAS).Both groups showed highly significant clinical improvements from baseline to the follow-ups at 24 and 60 months on all subscales of KOOS, Lysholm Knee Scoring Scale and VAS (p < 0.0001). No group differences were found at any of the testing occasions. One third of the patients that were treated with exercise therapy alone did not feel better after the treatment but were improved after arthroscopic surgery. According to radiographic findings two patients from each group had a slight progression of their osteoarthritis after 5 years.The findings indicate that arthroscopic surgery followed by exercise therapy was not superior to the same exercise therapy alone for this type of patients. Consequently, exercise therapy can be recommended as initial treatment. However, one third of the patients from the exercise group still had disabling knee symptoms after exercise therapy but improved to the same level as the rest of the patients after arthroscopic surgery with partial meniscectomy.I.
To compare the safety and efficacy of two different approaches of platelet-rich plasma (PRP) production methods as intra-articular injection treatment for knee cartilage degenerative lesions and osteoarthritis (OA).The study involved 144 symptomatic patients affected by cartilage degenerative lesions and OA. Seventy-two patients were treated with 3 injections of platelet concentrate prepared with a single-spinning procedure (PRGF), the other 72 with 3 injections of PRP obtained with a double-spinning approach. The patients were evaluated prospectively at the enrollment and at 2, 6, and 12 months’ follow-up with IKDC, EQ-VAS and Tegner scores; adverse events and patient satisfaction were also recorded.Both treatment groups presented a statistically significant improvement in all the scores evaluated at all the follow-up times. Better results were achieved in both groups in younger patients with a lower degree of cartilage degeneration. The comparative analysis showed similar improvements with the two procedures: in particular, IKDC subjective evaluation increased from 45.0 ± 10.1 to 59.0 ± 16.2, 61.3 ± 16.3, and 61.6 ± 16.2 at 2, 6, and 12 months in the PRGF group, and from 42.1 ± 13.5 to 60.8 ± 16.6, 62.5 ± 19.9, and 59.9 ± 20.0 at 2, 6, and 12 months in the PRP group, respectively. Concerning adverse events, more swelling (P = 0.03) and pain reaction (P = 0.0005), were found after PRP injections.Although PRP injections produced more pain and swelling reaction with respect to that produced by PRGF, similar results were found at the follow-up times, with a significant clinical improvement with respect to the basal level. Better results were achieved in younger patients with a low degree of cartilage degeneration.II.
In the present study, the clinical outcomes and second-look arthroscopic findings of intra-articular injection of stem cells with arthroscopic lavage for treatment of elderly patients with knee osteoarthritis (OA) were evaluated.Stem cell injections combined with arthroscopic lavage were administered to 30 elderly patients (≥65 years) with knee OA. Subcutaneous adipose tissue was harvested from both buttocks by liposuction. After stromal vascular fractions were isolated, a mean of 4.04 × 106 stem cells (9.7 % of 4.16 × 107 stromal vascular fraction cells) were prepared and injected in the selected knees of patients after arthroscopic lavage. Outcome measures included the Knee Injury and Osteoarthritis Outcome Scores, visual analog scale, and Lysholm score at preoperative and 3-, 12-, and 2-year follow-up visits. Sixteen patients underwent second-look arthroscopy.Almost all patients showed significant improvement in all clinical outcomes at the final follow-up examination. All clinical results significantly improved at 2-year follow-up compared to 12-month follow-up (P 65 years, only five patients demonstrated worsening of Kellgren–Lawrence grade. On second-look arthroscopy, 87.5 % of elderly patients (14/16) improved or maintained cartilage status at least 2 years postoperatively. Moreover, none of the patients underwent total knee arthroplasty during this 2-year period.Adipose-derived stem cell therapy for elderly patients with knee OA was effective in cartilage healing, reducing pain, and improving function. Therefore, adipose-derived stem cell treatment appears to be a good option for OA treatment in elderly patients.Therapeutic case series study, Level IV.
Platelet-rich plasma (PRP) is a natural concentrate of autologous blood growth factors experimented in different fields of medicine in order to test its potential to enhance tissue regeneration. The aim of our study is to explore this novel approach to treat degenerative lesions of articular cartilage of the knee. One hundred consecutive patients, affected by chronic degenerative condition of the knee, were treated with PRP intra-articular injections (115 knees treated). The procedure consisted of 150-ml of venous blood collected and twice centrifugated: 3 PRP units of 5 ml each were used for the injections. Patients were clinically prospectively evaluated before and at the end of the treatment, and at 6 and 12 months follow-up. IKDC, objective and subjective, and EQ VAS were used for clinical evaluation. Statistical analysis was performed to evaluate the significance of sex, age, grade of OA and BMI. A statistically significant improvement of all clinical scores was obtained from the basal evaluation to the end of the therapy and at 6–12 months follow-up (P < 0.0005). The results remained stable from the end of the therapy to 6 months follow up, whereas they became significantly worse at 12 months follow up (P = 0.02), even if still significantly higher respect to the basal level (P < 0.0005). The preliminary results indicate that the treatment with PRP injections is safe and has the potential to reduce pain and improve knee function and quality of live in younger patients with low degree of articular degeneration.
The aim of this study was to summarize all eligible studies to compare the effectiveness of treatment strategies for osteochondral defects (OCD) of the talus. Electronic databases from January 1966 to December 2006 were systematically screened. The proportion of the patient population treated successfully was noted, and percentages were calculated. For each treatment strategy, study size weighted success rates were calculated. Fifty-two studies described the results of 65 treatment groups of treatment strategies for OCD of the talus. One randomized clinical trial was identified. Seven studies described the results of non-operative treatment, 4 of excision, 13 of excision and curettage, 18 of excision, curettage and bone marrow stimulation (BMS), 4 of an autogenous bone graft, 2 of transmalleolar drilling (TMD), 9 of osteochondral transplantation (OATS), 4 of autologous chondrocyte implantation (ACI), 3 of retrograde drilling and 1 of fixation. OATS, BMS and ACI scored success rates of 87, 85 and 76%, respectively. Retrograde drilling and fixation scored 88 and 89%, respectively. Together with the newer techniques OATS and ACI, BMS was identified as an effective treatment strategy for OCD of the talus. Because of the relatively high cost of ACI and the knee morbidity seen in OATS, we conclude that BMS is the treatment of choice for primary osteochondral talar lesions. However, due to great diversity in the articles and variability in treatment results, no definitive conclusions can be drawn. Further sufficiently powered, randomized clinical trials with uniform methodology and validated outcome measures should be initiated to compare the outcome of surgical strategies for OCD of the talus
Microfracture is a well-established treatment procedure for chondral defects in high-demand population with good short-term results. The purpose of our study was to evaluate long-term clinical outcome of microfracture treatment in athletes with full-thickness chondral defects.Between 1991 and 2001, 170 patients were treated with microfracture for full-thickness knee chondral lesions at our institute and 67 of them were included in this study and prospectively followed up. Sixty-one athletes (91 %) were available at final follow-up (average 15.1 years). Average lesion size was 401 ± 27 mm2. Lysholm, Tegner and International Knee Documentation Committee (IKDC) (subjective–objective) scores were utilized pre-operatively and at 2-year, 5-year and final follow-up; Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS) and Marx scores were also collected at final follow-up.IKDC, Lysholm and Tegner scores increased significantly at 2 years, but gradually deteriorated at long term; however, average scores were significantly above baseline at final follow-up. Seven patients (11 %) were considered as failures as they underwent another operation because of reinjury or persistent pain during the first 5 years. Pain and swelling during strenuous activities was reported only in nine patients by the end of 2 years and in 35 patients at final follow-up. Patients with smaller lesions (≤400 mm²) and younger patients (≤30 years) showed significantly better results in KOOS, VAS and Marx scores. Radiographs performed at final follow-up showed evidence of progression of osteoarthritis changes in 40 % of the knees, with higher rate in older patients with large or multiple lesions (p < 0.05).Microfracture when applied in young patients with smaller lesions can offer good clinical results at short- and long-term follow-up; lesion size is more important prognostic factor of outcome than age. Deterioration of the clinical outcome should be expected after 2 and 5 years post-treatment, and degenerative changes are present at long-term follow-up, with higher rate in older athletes with large, multiple lesions.IV.
The purpose of this article is to present recommendations for new muscle strength and hop performance criteria prior to a return to sports after anterior cruciate ligament (ACL) reconstruction.A search was made of relevant literature relating to muscle function, self-reported questionnaires on symptoms, function and knee-related quality of life, as well as the rate of re-injury, the rate of return to sports and the development of osteoarthritis after ACL reconstruction. The literature was reviewed and discussed by the European Board of Sports Rehabilitation in order to reach consensus on criteria for muscle strength and hop performance prior to a return to sports.The majority of athletes that sustain an (ACL) injury do not successfully return to their pre-injury sport, even though most athletes achieve what is considered to be acceptable muscle function. On self-reported questionnaires, the athletes report high ratings for fear of re-injury, low ratings for their knee function during sports and low ratings for their knee-related quality of life.The conclusion is that the muscle function tests that are commonly used are not demanding enough or not sensitive enough to identify differences between injured and non-injured sides. Recommendations for new criteria are given for the sports medicine community to consider, before allowing an athlete to return to sports after an ACL reconstruction. IV.
Recently, the configuration of the anterior cruciate ligament (ACL) from its direct femoral insertion to midsubstance was found to be flat. This might have an important impact for anatomical ACL reconstruction. The purpose of this anatomical study was to evaluate the macroscopic appearance of the ACL from femoral to midsubstance.The ACL was dissected in 111 human fresh frozen cadaver knees from its femoral insertion to midsubstance, and the shape was described. The anatomical findings were documented on digital photographs and on video. Thirty knees were sent for computed tomography (CT), magnetic resonance imaging (MRI) and histology of the femoral ACL insertion.Two millimetres from its direct femoral insertion, the ACL fibres formed a flat ribbon in all dissected knees without a clear separation between AM and PL bundles. The ribbon was in exact continuity of the posterior femoral cortex. The width of the ribbon was between 11.43 and 16.18 mm and the thickness of the ACL was only 2.54–3.38 mm. 3D CT, MRI and the histological examination confirmed above findings.This is a detailed anatomical study describing the ribbon-like structure of the ACL from its femoral insertion to midsubstance. A key point was to carefully remove the surface fibrous membrane of the ACL. A total of 2–3 mm from its bony femoral insertion, the ACL formed a flat ribbon without a clear separation between AM and PL bundles. The ribbon was in exact continuity of the posterior femoral cortex. The findings of a flat ligament may change the future approach to femoral ACL footprint and midsubstance ACL reconstruction and to graft selection.
Platelet-rich plasma (PRP) therapy is a simple, low-cost and minimally invasive method that provides a natural concentrate of autologous blood growth factors (GFs) that can be used to enhance tissue regeneration. In a previous analysis of a 12-month follow-up study, promising results were obtained when treating patients affected by knee degeneration with PRP intra-articular injections. The main purpose of this study was to investigate the persistence of the beneficial effects observed.Of the 91 patients evaluated in the previous 12-month follow-up study, 90 were available for the 2-year follow-up (24 patients presented a bilateral lesion, in a total of 114 knees treated). All of the patients presented a chronic knee degenerative condition and were treated with three intra-articular PRP injections. IKDC and EQ-VAS scores were used for clinical evaluation. Complications, adverse events and patient satisfaction were also recorded.All of the evaluated parameters worsened at the 24-month follow-up: these parameters were at significantly lower levels with respect to the 12-month evaluation (the IKDC objective evaluation fell from 67 to 59% of normal and nearly normal knees; the IKDC subjective score fell from 60 to 51), even if they remained higher than the basal level. Further analysis showed better results in younger patients (P = 0.0001) and lower degrees of cartilage degeneration (P < 0.0005). The median duration of the clinical improvement was 9 months.These findings indicate that treatment with PRP injections can reduce pain and improve knee function and quality of life with short-term efficacy. Further studies are needed to confirm these results and understand the mechanism of action, and to find other application modalities, with different platelet and GF concentrations and injection timing, which provide better and more durable results.
To compare the effectiveness of intraarticular (IA) multiple and single platelet-rich plasma (PRP) injections as well as hyaluronic acid (HA) injections in different stages of osteoarthritis (OA) of the knee.A total of 162 patients with different stages of knee OA were randomly divided into four groups receiving 3 IA doses of PRP, one dose of PRP, one dose of HA or a saline injection (control). Then, each group was subdivided into two groups: early OA (Kellgren–Lawrence grade 0 with cartilage degeneration or grade I–III) and advanced OA (Kellgren–Lawrence grade IV). The patients were evaluated before the injection and at the 6-month follow-ups using the EuroQol visual analogue scale (EQ-VAS) and International Knee Documentation Committee (IKDC) subjective scores. Adverse events and patient satisfaction were recorded.There was a statistically significant improvement in the IKDC and EQ-VAS scores in all the treatment groups compared with the control group. The knee scores of patients treated with three PRP injections were significantly better than those patients of the other groups. There was no significant difference in the scores of patients injected with one dose of PRP or HA. In the early OA subgroups, significantly better clinical results were achieved in the patients treated with three PRP injections, but there was no significant difference in the clinical results of patients with advanced OA among the treatment groups.The clinical results of this study suggest IA PRP and HA treatment for all stages of knee OA. For patients with early OA, multiple (3) PRP injections are useful in achieving better clinical results. For patients with advanced OA, multiple injections do not significantly improve the results of patients in any group.I.
The aim of this study was to identify the minimal clinically important difference (MCID) in the Oxford knee score (OKS) and Short Form (SF-) 12 score after total knee arthroplasty (TKA).Prospective pre-operative and 1 year post-operative OKS and SF-12 scores for 505 patients undergoing a primary TKA for osteoarthritis were collected during a one-year period. Patient satisfaction with their (1) patient relief and (2) functional outcome was used as the anchor questions. Their response to each question was recorded using a 5-point Likert scale: excellent, very well, well, fair, and poor. Simple linear regression was used to calculate the MCID for improvement in the OKS and physical component of the SF-12 score according to the level of patient satisfaction with their pain relief and function.The OKS improved by 15.5 (95 % CI 14.7–16.4) points and the SF-12 physical component score improved by 10.1 (95 % CI 9.1–11.2) points for the study cohort. The level of patient satisfaction with their pain relief and function correlated with the improvement in the OKS (r = 0.56; p < 0.001, and r = 0.56; p < 0.001) and the physical component of the SF-12 score (r = 0.51; p < 0.001, and r = 0.60; p < 0.001), respectively. The MCID for the OKS was 5.0 (95 % CI 4.4–5.5) and 4.3 (95 % CI 3.8–4.8) points and for the physical component of the SF-12, it was 4.5 (95 % CI 3.9–5.2) and 4.8 (95 % CI 4.2–5.4) points for pain relief and function, respectively.The MCID identified for the OKS and SF-12 physical component score after TKA is the best available estimate and can be used to power studies and ensure that a statistical difference is also recognised by a patient.Retrospective diagnostic study, Level III.
This anatomical cadaver study was performed to investigate the flat appearance of the midsubstance shape of the anterior cruciate ligament (ACL) and its tibial “C”-shaped insertion site.The ACL midsubstance and the tibial ACL insertion were dissected in 20 cadaveric knees (n = 6 fresh frozen and n = 14 paraffined). Magnifying spectacles were used for all dissections. Morphometric measurements were performed using callipers and on digital photographs.In all specimens, the midsubstance of the ACL was flat with a mean width of 9.9 mm, thickness of 3.9 mm and cross-sectional area of 38.7 mm2. The “direct” “C”-shaped tibial insertion runs from along the medial tibial spine to the anterior aspect of the lateral meniscus. The mean width (length) of the “C” was 12.6 mm, its thickness 3.3 mm and area 31.4 mm2. The centre of the “C” was the bony insertion of the anterior root of the lateral meniscus overlayed by fat and crossed by the ACL. No posterolateral (PL) inserting ACL fibres were found. Together with the larger “indirect” part (area 79.6 mm2), the “direct” one formed a “duck-foot”-shaped footprint.The tibial ACL midsubstance and tibial “C”-shaped insertion are flat and are resembling a “ribbon”. The centre of the “C” is the bony insertion of the anterior root of the lateral meniscus. There are no central or PL inserting ACL fibres. Anatomical ACL reconstruction may therefore require a flat graft and a “C”-shaped tibial footprint reconstruction with an anteromedial bone tunnel for single bundle and an additional posteromedial bone tunnel for double bundle.
The acetabular labrum is theorized to be important to normal hip function by providing stability to distraction forces through the suction effect of the hip fluid seal. The purpose of this study was to determine the relative contributions of the hip capsule and labrum to the distractive stability of the hip, and to characterize hip stability to distraction forces in six labral conditions: intact labrum, labral tear, labral repair (looped vs. through sutures), partial resection, labral reconstruction with iliotibial band, and complete resection.Eight cadaveric hips with a mean age of 47.8 years (SD 4.3, range 41–51 years) were included. For each condition, the hip seal was broken by distracting the hip at a rate of 0.33 mm/s while the required force, energy, and negative intra-articular pressure were measured. For comparisons between labral conditions, measurements were normalized to the intact labral state (percent of intact).The relative contribution of the labrum to distractive stability was greatest at 1 and 2 mm of displacement, where it was significantly greater than the role of the capsule and accounted for 77 % (SD 27 %, p = 0.006) and 70 % (SD 7 %, p = 0.009) of total distractive stability, respectively. The relative contribution of the capsule to distractive stability increased with progressive displacement, providing 41 % (SD 49 %) and 52 % (SD 53 %) of distractive stability at 3 and 5 mm of distraction, respectively. The maximal distraction force required to break the hip seal in the intact labral state (capsule removed) varied from 124 to 150 N. Labral tear, partial resection, and complete resection resulted in average maximal distraction forces of 76 % (SD 34 %), 29 % (SD 26 %), and 27 % (SD 22 %), respectively, compared to the intact state. Through type labral repairs resulted in significantly greater improvements (from the labral tear state) in maximal negative pressure generated, compared to looped type repairs (median increase; +32 vs. −9 %, p = 0.029). Labral reconstruction resulted in a mean maximal distraction force of 66 % (SD 35 %), with a significant improvement of 37 % compared to partial labral resection (p < 0.001).The acetabular labrum was the primary hip stabilizer to distraction forces at small displacements (1–2 mm). Partial labral resection significantly decreased the distractive strength of the hip fluid seal. Labral reconstruction significantly improved distractive stability, compared to partial labral resection. The results of this study may provide insight into the relative importance of the capsule and labrum to distractive stability of the hip and may help to explain hip microinstability in the setting of labral disease.
Performing kinematically aligned total knee arthroplasty (TKA) with generic instruments is less costly than patient-specific instrumentation; however, the alignment and function with this new technique are unknown.One hundred and one consecutive patients (101 knees) treated with kinematically aligned TKA, implanted with use of generic instruments, were prospectively followed. The medial collateral ligament was not released. The lateral collateral ligament was released in the 17 % of patients with a fixed valgus deformity. Six measures of alignment were categorized from a scanogram of the extremity, an axial scan of the knee, and an intraoperative measurement. Both the Oxford Knee and WOMAC™ scores were assessed as function. High function was a mean Oxford Knee score >41.The frequency that patients were categorized as in-range was 93 % for the mechanical alignment of the limb (0° ± 3°), 94 % for the joint line (−3° ± 3°), 57 % for the anatomic axis of the knee (−2.5° ± −7.4° valgus), 4 % for the varus–valgus rotation of the tibial component (≤0° valgus), 98 % for the rotation of the tibial component with respect to the femoral component (0° ± 10°), and 94 % for the intraoperative change in the anterior–posterior distance of the tibia with respect to the femur at 90° of flexion (0 ± 2 mm). The mean OKS score was 42, and WOMAC™ score was 89. For each alignment, the function was the same for patients categorized as an outlier or in-range.The authors prefer the use of generic instruments to perform kinematically aligned TKA in place of mechanically aligned TKA because five of six alignments were accurate and because high function was restored regardless of whether patients had an alignment categorized as an outlier or in-range.IV.
In the past decades, considerable efforts have been made to propose experimental and clinical treatments for articular cartilage defects. Yet, the problem of cartilage defects extending deep in the underlying subchondral bone has not received adequate attention. A profound understanding of the basic anatomic aspects of this particular site, together with the pathophysiology of diseases affecting the subchondral bone is the key to develop targeted and effective therapeutic strategies to treat osteochondral defects. The subchondral bone consists of the subchondral bone plate and the subarticular spongiosa. It is separated by the cement line from the calcified zone of the articular cartilage. A variable anatomy is characteristic for the subchondral region, reflected in differences in thickness, density, and composition of the subchondral bone plate, contour of the tidemark and cement line, and the number and types of channels penetrating into the calcified cartilage. This review aims at providing insights into the anatomy, morphology, and pathology of the subchondral bone. Individual diseases affecting the subchondral bone, such as traumatic osteochondral defects, osteochondritis dissecans, osteonecrosis, and osteoarthritis are also discussed. A better knowledge of the basic science of the subchondral region, together with additional investigations in animal models and patients may translate into improved therapies for articular cartilage defects that arise from or extend into the subchondral bone