Hayden G. Morris

The anatomy and reconstruction of the medial patellofemoral ligament

INTRODUCTION Reconstruction of the MPFL for recurrent and acute lateral dislocation of the patella is becoming more accepted. This study aimed to further define the medial patellofemoral ligament (MPFL) anatomy and to describe the most suitable sites for graft attachment when reconstructing the MPFL. MATERIALS AND METHODS Anatomical dissection was performed on 25 embalmed knee specimens. Four separate specimens were used to assess graft fixation points. Sites were tested for isometricity from 0 to 120 degrees of knee flexion. Length patterns were considered isometric if there was less than 5 mm of length change throughout range of motion. RESULTS The MPFL attaches from the posterior part of the medial epicondyle, to the superomedial patella, the under-surface of vastus medialis, and the quadriceps tendon. Optimal attachment points for an MPFL graft were the superior patella and the femoral attachment points of the MPFL (just distal to the adductor tubercle) and points posterior and inferior to this. CONCLUSION We have defined the anatomy and kinematics of the MPFL with reconstruction of this ligament in mind.

Delayed- and non-union following opening wedge high tibial osteotomy: surgeons’ results from 182 completed cases

Opening wedge high tibial osteotomy (OWHTO) is a recently described procedure for medial compartment arthritis of the knee in the active, younger population. Despite having a number of advantages over the traditional closing wedge high tibial osteotomy (CWHTO) a potential complication of OWHTO is a high rate of delayed- and non-union. This study reports the occurrence of delayed- and non-union following OWHTO for medial compartment arthritis of the knee. Questionnaires were sent to all current members of the Australian Knee Society (n=45), a special interest group of the Australian Orthopaedic Group. Surgeons were asked primarily to indicate how many OWHTOs they had performed, and how many of these had progressed to union, delayed-union and non-union. All 45 questionnaires were returned, with 21 surgeons (47%) performing OWHTOs. A total of 188 OWHTO cases were reported, of which 182 were complete. Of these complete cases 167 (91.8%) were classed as united, 12 (6.6%) delay-united and 3 (1.6%) non-united. The results of this study demonstrate that the rate of delayed- and non-union following OWHTO for medial compartment arthritis of the knee is relatively low and comparable to that reported for traditional CWHTO.

Patellofemoral osteoarthritis is prevalent and associated with worse symptoms and function after hamstring tendon autograft ACL reconstruction

Objectives To evaluate the compartmental distribution of knee osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR), to determine if patellofemoral or tibiofemoral OA is more strongly associated with knee symptoms and function, and to evaluate the contribution of associated injuries and surgical delay to the development of OA. Methods This cross-sectional study recruited 70 participants who underwent hamstring tendon (HT) ACLR 5–10 years previously. Radiographic OA was assessed according to the Osteoarthritis Research Society International (OARSI) criteria. Knee symptoms were assessed with the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Anterior Knee Pain Scale (AKPS), while function was assessed with three lower limb tasks (hop-for-distance, one-leg rise and side-hop). Multivariate and binary logistic regression analyses were performed to assess the relationship between OA and symptomatic/functional outcomes and associated injuries/surgical delay, respectively. Results Radiographic OA was observed in the patellofemoral (47%) and tibiofemoral joints (31%). Pain, symptoms and quality of life on the KOOS and the AKPS were associated with severity of patellofemoral OA (standardised regression coefficient (β)=−0.3 to −0.5, p=0.001–0.042), whereas only the KOOS-pain subscale was associated with tibiofemoral OA (β=−0.3, p=0.037). For each functional task, greater patellofemoral OA severity was associated with worse performance, independent of tibiofemoral OA severity (β=−0.3 to −0.4, p=0.001–0.026). Medial meniscal and patellofemoral chondral lesions at surgery were associated with tibiofemoral and patellofemoral OA development at follow-up, respectively, while a longer surgery delay was associated with patellofemoral OA. Conclusions Patellofemoral OA is common following HT ACLR and is associated with worse knee-related symptoms, including anterior knee pain, and decreased functional performance.

Arthroscopically treated intraarticular osteoid osteoma in the ankle--a report of 3 cases.

We present 3 cases of arthroscopically treated intraarticular osteoid osteoma of the ankle. Emphasis is on the high index of suspicion for this lesion, the appropriate imaging modality and the efficacy of arthroscopic excision of these tumors with superficial location in the talus and tibial plafond.

MRI-negative bucket-handle tears of the lateral meniscus in athletes: a case series

Magnetic resonance imaging (MRI) is the most widely used non-invasive test for assessing intra-articular injuries of the knee. It has been suggested that a negative MRI can be useful in avoiding the need for diagnostic arthroscopy in cases where clinical examination is equivocal. However, the sensitivity and specificity of MRI is not 100%, particularly for tears of the lateral meniscus. Furthermore, a false negative MRI scan may result in premature return to play in athletes, resulting in increased risk of further damage to a torn meniscus. To illustrate this issue, we present a case series of eight elite athletes who all presented with mechanical knee symptoms and where MRI scans revealed no significant intra-articular pathology. Five of the athletes were allowed to return to sport on the basis of a negative MRI. All patients were subsequently found to have a bucket-handle tear of their lateral meniscus at arthroscopy. Two independent, experienced musculoskeletal radiologists were asked to review the MRI films without being given any clinical history of the cases. Although injuries to the popliteus tendon were noted in two of the athletes who had sustained a recent acute injury to their knee, no meniscal tears were identified. Thus arthroscopy remains the gold standard for the assessment and management of high-demand patients with a clinical suspicion of meniscal pathology.

Medium to long‐term results of the UNIX uncemented unicompartmental knee replacement

INTRODUCTION We report the first non-designer study of the Unix uncemented unicompartmental knee prosthesis. MATERIALS AND METHODS Eighty-five consecutive UKRs were carried out with sixty-five available for follow-up. Oxford Knee Scores, WOMAC questionnaire and radiological assessment were completed. RESULTS The mean Oxford Knee Score was thirty-eight and WOMAC Score was twenty. Overall Kaplan Meier survival estimate is 76% (95% confidence interval 60%-97%) at 12years and 88% (95% confidence interval 76-100%) with aseptic loosening as the endpoint. Radiographic assessment showed lysis in the tibia in 6% of patients with no lysis evident around the central fin. DISCUSSION Survivorship is comparable to other published series of UKRs. We suggest the central fin design is key to dissipating large forces throughout the proximal tibia, resulting in low levels of tibial loosening. Level of evidence IV.

Early Patellofemoral Osteoarthritis Features One Year After Anterior Cruciate Ligament Reconstruction: Symptoms and Quality of Life at Three Years.

To determine whether the presence of magnetic resonance imaging (MRI) osteoarthritis (OA) features in the patellofemoral or tibiofemoral joint (i.e., bone marrow lesions, cartilage lesions, and osteophytes) and/or functional impairments, 1 year following anterior cruciate ligament reconstruction (ACLR), can predict Knee Injury and Osteoarthritis Outcome Score (KOOS) at 3 years.

The Macroscopic Arthroscopic Anatomy of the Infrapatellar Fat Pad

PURPOSE Our purpose was to define the macroscopic anatomy of the infrapatellar fat pad (IFP) when viewed at arthroscopy and to document the common variations. METHODS Ninety-six consecutive patients between 8 and 50 years of age with no previous knee surgery or fat pad pathology underwent arthroscopic examination of the knee. The fat pad of each patient was observed and described regarding size, color, consistency, and the presence of lobules, villous synovium, and lingulae. RESULTS The macroscopic arthroscopic anatomy of the IFP was defined. Male fat pads were larger than female fat pads. Two separate parts were described-medial and lateral-with medial dominence being most typical. The specific normal anatomic appearance of each section was defined regarding size, color, consistency, and attributes. Ligamentum mucosum, as the separation limit between the sections, was found in most knees. CONCLUSIONS The macroscopic anatomy of the IFP is described at arthroscopy performed for internal pathology of the knee. Two distinct parts were defined-medial and lateral-with medial dominance. A typical fat pad was yellow and included an infrapatellar lingula (85%), lobulation (65%), and villous synovium (65%). We found a ligamentum mucosum in 79% of cases. CLINICAL RELEVANCE Knowledge of the macroscopic anatomy of the IFP and variations will allow the accurate diagnosis of pathology of the fat pad, rather than being a diagnosis of exclusion.

Polyethylene thickness in unicompartmental knee arthroplasty.

Inadequate polyethylene thickness is a risk factor in the development of polyethylene wear in unicompartmental knee arthroplasty (UKA). The labelled thickness of polyethylene inserts often refers to the combined thickness of the insert and its metal backing. However specific information regarding the actual minimum thickness of the polyethylene is seldom available. We sought to determine the actual minimum thickness of polyethylene inserts used in five contemporary metal-backed UKA designs. The thinnest available insert from each of these designs was identified and measured at the lowest point of its concave articulating surface with a Kincrome electronic digital micrometer. The minimum thickness of the inserts ranged from 3.702 mm to 7.859 mm (mean values). In two of the inserts, the minimum thickness was found to be less than the recommended minimum thickness of 6mm. Implant manufacturers should clearly indicate the actual minimum thickness of polyethylene inserts on their product labels.

Predictors and effects of patellofemoral pain following hamstring-tendon ACL reconstruction

OBJECTIVES Patellofemoral pain is a frequent and troublesome complication following anterior cruciate ligament reconstruction (ACLR), irrespective of graft source. Yet, little is known about the factors associated with patellofemoral pain following hamstring-tendon ACLR. DESIGN Retrospective analysis of potential patellofemoral pain predictors, and cross-sectional analysis of possible patellofemoral pain consequences. METHODS Potential predictors (pre-injury patellofemoral pain and activity level, concomitant patellofemoral cartilage damage and meniscectomy, age, sex, and surgical delay) and consequences (hopping performance, quality of life, kinesiophobia, and return to sport rates and attitudes) of patellofemoral pain 12 months following hamstring-tendon ACLR were assessed in 110 participants using univariate and multivariate analyses. RESULTS Thirty-three participants (30%) had patellofemoral pain at 12 months post-ACLR. Older age at the time of ACLR was the only predictor of post-operative patellofemoral pain. Following ACLR, those with patellofemoral pain had a higher body mass index, and worse physical performance, quality of life, kinesiophobia and return to sport attitudes. Patellofemoral pain has a significant burden on individuals 12 months following hamstring-tendon ACLR. CONCLUSIONS Clinicians need to be cognisant of patellofemoral pain, particularly in older individuals and those with a higher body mass index. The importance of considering psychological factors that are not typically addressed during ACLR rehabilitation, such as kinesiophobia, quality of life and return to sport attitudes is emphasised.