We have investigated whether shape of the knee can predict the clinical outcome of patients after an anterior cruciate ligament rupture. We used statistical shape modelling to measure the shape of the knee joint of 182 prospectively followed patients on lateral and Rosenberg view radiographs of the knee after a rupture of the anterior cruciate ligament. Subsequently, we associated knee shape with the International Knee Documentation Committee subjective score at two years follow-up. The mean age of patients was 31 years (21 to 51), the majority were male (n = 121) and treated operatively (n = 135). We found two modes (shape variations) that were significantly associated with the subjective score at two years: one for the operatively treated group (p = 0.002) and one for the non-operatively treated group (p = 0.003). Operatively treated patients who had higher subjective scores had a smaller intercondylar notch and a smaller width of the intercondylar eminence. Non-operatively treated patients who scored higher on the subjective score had a more pyramidal intercondylar notch as opposed to one that was more dome-shaped. We conclude that the shape of the femoral notch and the intercondylar eminence is predictive of clinical outcome two years after a rupture of the anterior cruciate ligament. Cite this article: Bone Joint J 2014;96-B:737–42

Between 1993 and 1994, 891 patients underwent primary anterior cruciate ligament (ACL) reconstruction. A total of 48 patients had undergone bilateral ACL reconstruction and 42 were available for review. These patients were matched to a unilateral ACL reconstruction control group for gender, age, sport of primary injury, meniscal status and graft type. At 15-year follow-up a telephone interview with patients in both groups was performed. The incidence of further ACL injury was identified through structured questions and the two groups were compared for the variables of graft rupture or further ACL injury, family history of ACL injury, International Knee Documentation Committee (IKDC) subjective score and activity level. There were 28 male and 14 female patients with a mean age of 25 years (13 to 42) at the time of first ACL injury. Subsequent further ACL injury was identified in ten patients (24%) in the bilateral ACL reconstruction study group and in nine patients (21%) in the unilateral ACL reconstruction control group (p = 0.794). The mean time from bilateral ACL reconstruction to further ACL injury was 54 months (6 to 103). There was no significant difference between the bilateral ACL reconstruction study group and the matched unilateral ACL reconstruction control group in incidence of further ACL injury (p = 0.794), family history of ACL injury (p = 0.595), IKDC activity level (p = 0.514), or IKDC subjective score (p = 0.824). After bilateral ACL reconstruction the incidence of graft rupture and subjective outcomes were equivalent to that after unilateral ACL reconstructions. Cite this article: Bone Joint J 2013;95-B:798–802

Aims. To examine the rates of hamstring graft salvage with arthroscopic debridement of infected anterior cruciate ligament (ACL) reconstruction as reported in the literature and discuss functional outcomes. Materials and Methods. A search was performed without language restriction on PubMed, EMBASE, Ovid, CINAHL and Cochrane Register of Controlled Trials (CENTRAL) databases from their inception to April 2015. We identified 147 infected hamstring grafts across 16 included studies. Meta-analysis was performed using a random-effects model to estimate the overall graft salvage rate, incorporating two different definitions of graft salvage. Results. The graft salvage rate was 86% (95% confidence intervals (CI) 73% to 93%; heterogeneity: tau. 2. = 1.047, I. 2. = 40.51%, Q = 25.2, df = 15, p < 0.001), excluding ACL re-ruptures. Including re-ruptures as failures, the graft salvage rate was 85% (95% CI 76% to 91%; heterogeneity: tau. 2.  = 0.099, I. 2. = 8.15%, Q = 14.15, df = 13, p = 0.36). Conclusions. Arthroscopic debridement combined with antibiotic treatment can lead to successful eradication of infection and graft salvage, with satisfactory functional outcomes in many cases of septic arthritis following ACL reconstruction. Persistent infection despite repeat arthroscopic debridements requires graft removal with the intention of revision ACL surgery at a later stage. Take home message: Arthroscopic debridement combined with antibiotic therapy is an appropriate initial approach in most cases of septic arthritis following ACL reconstruction, achieving graft salvage rates of about 85%. Cite this article: Bone Joint J 2016;98-B:608–15

We report on the long-term results of 163 bicruciate-retaining Hermes 2C total knee replacements in 130 patients at a mean follow-up of 22.4 years (20.3 to 23.5). Even when the anterior cruciate ligament had a partially degenerative appearance it was preserved as long as the knee had a normal anterior drawer and Lachman’s test pre-operatively. The description and surgical technique of this minimally constrained prosthesis were published in 1983 and the ten-year clinical results in 1999. A total of 12% of the knees (20 of 163) in this study were revised because of wear of the polyethylene tibial insert. Excellent stability was achieved and the incidence of aseptic component loosening was 4.3% (seven of 163). The survival rate using revision for any reason as the endpoint was 82% (95% confidence interval 76.2 to 88.0). Although this series included a relatively small number of replacements, it demonstrated that the anterior cruciate ligament, even when partially degenerated at the time of TKR, remained functional and provided adequate stability at a long-term follow-up. Cite this article: Bone Joint J 2013;95-B:917–22

Aims

The cemented Oxford unicompartmental knee arthroplasty (OUKA) features two variants: single and twin peg OUKA. The purpose of this study was to assess the stability of both variants in a worst-case scenario of bone defects and suboptimal cementation.

Artificial intelligence and machine-learning analytics have gained extensive popularity in recent years due to their clinically relevant applications. A wide range of proof-of-concept studies have demonstrated the ability of these analyses to personalize risk prediction, detect implant specifics from imaging, and monitor and assess patient movement and recovery. Though these applications are exciting and could potentially influence practice, it is imperative to understand when these analyses are indicated and where the data are derived from, prior to investing resources and confidence into the results and conclusions. In this article, we review the current benefits and potential limitations of machine-learning for the orthopaedic surgeon with a specific emphasis on data quality.

Aims

Higher osteoblastic bone activity is expected in aseptic loosening and painful unicompartmental knee arthroplasty (UKA). However, insights into normal bone activity patterns after medial UKAs are lacking. The aim of this study was to identify the evolution in bone activity pattern in well-functioning medial mobile-bearing UKAs.

Aims

It is unknown whether gap laxities measured in robotic arm-assisted total knee arthroplasty (TKA) correlate to load sensor measurements. The aim of this study was to determine whether symmetry of the maximum medial and lateral gaps in extension and flexion was predictive of knee balance in extension and flexion respectively using different maximum thresholds of intercompartmental load difference (ICLD) to define balance.

Aims

There is little published on the outcomes after restarting elective orthopaedic procedures following cessation of surgery due to the COVID-19 pandemic. During the pandemic, the reported perioperative mortality in patients who acquired SARS-CoV-2 infection while undergoing elective orthopaedic surgery was 18% to 20%. The aim of this study is to report the surgical outcomes, complications, and risk of developing COVID-19 in 2,316 consecutive patients who underwent elective orthopaedic surgery in the latter part of 2020 and comparing it to the same, pre-pandemic, period in 2019.

We measured the sagittal laxity in 70 knee replacements at least six months after surgery, using a KT 1000 arthrometer. With an unconstrained prosthesis (the Oxford meniscal knee) anteroposterior stability was normal in joints known to have intact cruciate ligaments. There was increased laxity in those which lacked an anterior cruciate ligament. In knees with an intact anterior cruciate ligament, sagittal laxity did not increase with time

We investigated whether strontium-enriched calcium phosphate cement (Sr-CPC)-treated soft-tissue tendon graft results in accelerated healing within the bone tunnel in reconstruction of the anterior cruciate ligament (ACL). A total of 30 single-bundle ACL reconstructions using tendo Achillis allograft were performed in 15 rabbits. The graft on the tested limb was treated with Sr-CPC, whereas that on the contralateral limb was untreated and served as a control. At timepoints three, six, nine, 12 and 24 weeks after surgery, three animals were killed for histological examination. At six weeks, the graft–bone interface in the control group was filled in with fibrovascular tissue. However, the gap in the Sr-CPC group had already been completely filled in with new bone, and there was evidence of the early formation of Sharpey fibres. At 24 weeks, remodelling into a normal ACL–bone-like insertion was found in the Sr-CPC group. Coating of Sr-CPC on soft tissue tendon allograft leads to accelerated graft healing within the bone tunnel in a rabbit model of ACL reconstruction using Achilles tendon allograft. Cite this article: Bone Joint J 2013;95-B:923–8

From a search of MRI reports on knees, 20 patients were identified with evidence of early anteromedial osteoarthritis without any erosion of bone and a control group of patients had an acute rupture of the anterior cruciate ligament. The angle formed between the extension and flexion facets of the tibia, which is known as the extension facet angle, was measured on a sagittal image at the middle of the medial femoral condyle. The mean extension facet angle in the control group was 14° (3° to 25°) and was unrelated to age (Spearman’s rank coefficient, p = 0.30, r = 0.13). The mean extension facet angle in individuals with MRI evidence of early anteromedial osteoarthritis was 19° (13° to 26°, SD 4°). This difference was significant (Mann-Whitney U test, p < 0.001). A wide variation in the extension facet angle was found in the normal control knees and an association between an increased extension facet angle and MRI evidence of early anteromedial osteoarthritis. Although a causal link has not been demonstrated, we postulate that a steeper extension facet angle might increase the duration of loading on the extension facet during the stance phase of gait, and that this might initiate failure of the articular cartilage

We measured on the radiographs of 100 knees the length of the patellar ligament and the anterior cruciate ligament, and the distance between the tibial tubercle and the femoral insertion of the anterior cruciate. The length of the patellar ligament was always greater than that of the anterior cruciate ligament, but shorter than the distance between the tibial tubercle and the femoral insertion of the anterior cruciate by a mean of 14.2 mm (3 to 22). We conclude that anatomical, isometric replacement of the anterior cruciate is possible using a free graft, but not by the technique of retaining the tibial attachment originally described by Jones (1970)

Introduction. Osteoarthritis (OA) is a progressively debilitating disease that affects mostly cartilage, with associated changes in the bone. The increasing incidence of OA and an ageing population, coupled with insufficient therapeutic choices, has led to focus on the potential of stem cells as a novel strategy for cartilage repair. Methods. In this study, we used scaffold-free mesenchymal stem cells (MSCs) obtained from bone marrow in an experimental animal model of OA by direct intra-articular injection. MSCs were isolated from 2.8 kg white New Zealand rabbits. There were ten in the study group and ten in the control group. OA was induced by unilateral transection of the anterior cruciate ligament of the knee joint. At 12 weeks post-operatively, a single dose of 1 million cells suspended in 1 ml of medium was delivered to the injured knee by direct intra-articular injection. The control group received 1 ml of medium without cells. The knees were examined at 16 and 20 weeks following surgery. Repair was investigated radiologically, grossly and histologically using haematoxylin and eosin, Safranin-O and toluidine blue staining. Results. Radiological assessment confirmed development of OA changes after 12 weeks. Rabbits receiving MSCs showed a lower degree of cartilage degeneration, osteophyte formation, and subchondral sclerosis than the control group at 20 weeks post-operatively. The quality of cartilage was significantly better in the cell-treated group compared with the control group after 20 weeks. Conclusions. Bone marrow-derived MSCs could be promising cell sources for the treatment of OA. Neither stem cell culture nor scaffolds are absolutely necessary for a favourable outcome. Cite this article: Bone Joint Res 2014;3:32–7