Patella subluxation assessed on dynamic MRI has previously been shown to be associated with anterior knee pain. In this MRI study of 60 patients we investigated the relationship between subluxation and multiple bony, cartilaginous and soft-tissue factors that might predispose to subluxation using discriminant function analysis.

Patella engagement (% of patella cartilage overlapping with trochlea cartilage) had the strongest relationship with subluxation. Patellae with > 30% engagement tended not to sublux; those with < 30% tended to sublux. Other factors that were associated with subluxation included the tibial tubercle-trochlea notch distance, vastus medialis obliquus distance from patella, patella alta, and the bony and cartilaginous sulcus angles in the superior part of the trochlea. No relationship was found between subluxation and sulcus angles for cartilage and bone in the middle and lower part of the trochlea, cartilage thicknesses and Wiberg classification of the patella.

This study indicates that patella engagement is a key factor associated with patellar subluxation. This suggests that in patients with anterior knee pain with subluxation, resistant to conservative management, surgery directed towards improving patella engagement should be considered. A clinical trial is necessary to test this hypothesis.

The June 2014 Knee Roundup³⁶⁰ looks at: acute repair preferable in hamstring ruptures; osteoarthritis a given in ACL injury, even with reconstruction?; chicken and egg: patellofemoral dysfunction and hip weakness; meniscal root tears as bad as we thought; outcomes in the meniscus; topical NSAIDs have a measurable effect on synovitis; nailing for tibial peri-prosthetic fracture.

No previous studies have examined the physical characteristics of patients with cauda equina syndrome (CES). We compared the anthropometric features of patients who developed CES after a disc prolapse with those who did not but who had symptoms that required elective surgery. We recorded the age, gender, height, weight and body mass index (BMI) of 92 consecutive patients who underwent elective lumbar discectomy and 40 consecutive patients who underwent discectomy for CES. On univariate analysis, the mean BMI of the elective discectomy cohort (26.5 kg/m² (16.6 to 41.7) was very similar to that of the age-matched national mean (27.6 kg/m², p = 1.0). However, the mean BMI of the CES cohort (31.1 kg/m² (21.0 to 54.9)) was significantly higher than both that of the elective group (p < 0.001) and the age-matched national mean (p < 0.001). A similar pattern was seen with the weight of the groups. Multivariate logistic regression analysis was performed, adjusted for age, gender, height, weight and BMI. Increasing BMI and weight were strongly associated with an increased risk of CES (odds ratio (OR) 1.17, p < 0.001; and OR 1.06, p <  0.001, respectively). However, increasing height was linked with a reduced risk of CES (OR 0.9, p < 0.01). The odds of developing CES were 3.7 times higher (95% confidence interval (CI) 1.2 to 7.8, p = 0.016) in the overweight and obese (as defined by the World Health Organization: BMI ≥ 25 kg/m²) than in those of ideal weight. Those with very large discs (obstructing > 75% of the spinal canal) had a larger BMI than those with small discs (obstructing < 25% of the canal; p < 0.01). We therefore conclude that increasing BMI is associated with CES.

Mechanical alignment has been a fundamental tenet of total knee arthroplasty (TKA) since modern knee replacement surgery was developed in the 1970s. The objective of mechanical alignment was to infer the greatest biomechanical advantage to the implant to prevent early loosening and failure. Over the last 40 years a great deal of innovation in TKA technology has been focusing on how to more accurately achieve mechanical alignment. Recently the concept of mechanical alignment has been challenged, and other alignment philosophies are being explored with the intention of trying to improve patient outcomes following TKA.

This article examines the evolution of the mechanical alignment concept and whether there are any viable alternatives.

This short contribution aims to explain how intervertebral disc ‘degeneration’ differs from normal ageing, and to suggest how mechanical loading and constitutional factors interact to cause disc degeneration and prolapse. We suggest that disagreement on these matters in medico-legal practice often arises from a misunderstanding of the nature of ‘soft-tissue injuries’.

The pre-operative differentiation between enchondroma, low-grade chondrosarcoma and high-grade chondrosarcoma remains a diagnostic challenge. We reviewed the accuracy and safety of the radiological grading of cartilaginous tumours through the assessment of, first, pre-operative radiological and post-operative histological agreement, and second the rate of recurrence in lesions confirmed as high-grade on histology. We performed a retrospective review of major long bone cartilaginous tumours managed by curettage as low grade between 2001 and 2012. A total of 53 patients with a mean age of 47.6 years (8 to 71) were included. There were 23 men and 30 women. The tumours involved the femur (n = 20), humerus (n = 18), tibia (n = 9), fibula (n = 3), radius (n = 2) and ulna (n = 1). Pre-operative diagnoses resulted from multidisciplinary consensus following radiological review alone for 35 tumours, or with the addition of pre-operative image guided needle biopsy for 18. The histologically confirmed diagnosis was enchondroma for two (3.7%), low-grade chondrosarcoma for 49 (92.6%) and high-grade chondrosarcoma for two (3.7%). Three patients with a low-grade tumour developed a local recurrence at a mean of 15 months (12 to 17) post-operatively. A single high-grade recurrence (grade II) was treated with tibial diaphyseal replacement. The overall recurrence rate was 7.5% at a mean follow-up of 4.7 years (1.2 to 12.3). Cartilaginous tumours identified as low-grade on pre-operative imaging with or without additional image-guided needle biopsy can safely be managed as low-grade without pre-operative histological diagnosis. A few tumours may demonstrate high-grade features histologically, but the rates of recurrence are not affected.

Cite this article: Bone Joint J 2014; 96-B:1098–105.

In this case study, we describe the clinical presentation and treatment of 36 patients with periosteal chondrosarcoma collected over a 59-year period by the archive of the Netherlands Committee on Bone Tumours. The demographics, clinical presentation, radiological features, treatment and follow-up are presented with the size, location, the histological grading of the tumour and the survival.

We found a slight predominance of men (61%), and a predilection for the distal femur (33%) and proximal humerus (33%). The metaphysis was the most common site (47%) and the most common presentation was with pain (44%). Half the tumours were classified histologically as grade 1. Pulmonary metastases were reported in one patient after an intra-lesional resection. A second patient died from local recurrence and possible pulmonary and skin metastases after an incomplete resection.

It is clearly important to make the diagnosis appropriately because an incomplete resection may result in local recurrence and metastatic spread. Staging for metastatic disease is recommended in grade II or III lesions.

These patients should be managed with a contrast-enhanced MRI of the tumour and histological confirmation by biopsy, followed by en-bloc excision.

Cite this article: Bone Joint J 2014;96-B:823–8.

This protocol describes a pragmatic multicentre randomised controlled trial (RCT) to assess the clinical and cost effectiveness of arthroscopic and open surgery in the management of rotator cuff tears. This trial began in 2007 and was modified in 2010, with the removal of a non-operative arm due to high rates of early crossover to surgery.

Cite this article: Bone Joint Res 2014;3:155–60.

Intramedullary infection in long bones represents a complex clinical challenge, with an increasing incidence due to the increasing use of intramedullary fixation. We report a prospective case series using an intramedullary reaming device, the Reamer–Irrigator–Aspirator (RIA) system, in association with antibiotic cement rods for the treatment of lower limb long bone infections. A total of 24 such patients, 16 men and eight women, with a mean age of 44.5 years (17 to 75), 14 with femoral and 10 with tibial infection, were treated in a staged manner over a period of 2.5 years in a single referral centre. Of these, 21 patients had had previous surgery, usually for fixation of a fracture (seven had sustained an open fracture originally and one had undergone fasciotomies). According to the Cierny–Mader classification system, 18 patients were classified as type 1A, four as 3A (discharging sinus tract), one as type 4A and one as type 1B. Staphylococcus species were isolated in 20 patients (83.3%). Local antibiotic delivery was used in the form of impregnated cement rods in 23 patients. These were removed at a mean of 2.6 months (1 to 5). Pathogen-specific antibiotics were administered systemically for a mean of six weeks (3 to 18). At a mean follow-up of 21 months (8 to 36), 23 patients (96%) had no evidence of recurrent infection. One underwent a planned trans-tibial amputation two weeks post-operatively due to peripheral vascular disease and chronic recalcitrant osteomyelitis of the tibia and foot. The combination of RIA reaming, the administration of systemic pathogen-specific antibiotics and local delivery using impregnated cement rods proved to be a safe and efficient form of treatment in these patients.

Cite this article: Bone Joint J 2014; 96-B:783–8.

We retrospectively reviewed 30 patients with a diffuse-type giant-cell tumour (Dt-GCT) (previously known as pigmented villonodular synovitis) around the knee in order to assess the influence of the type of surgery on the functional outcome and quality of life (QOL). Between 1980 and 2001, 15 of these tumours had been treated primarily at our tertiary referral centre and 15 had been referred from elsewhere with recurrent lesions.

The mean follow-up was 64 months (24 to 393). Functional outcome and QOL were assessed with range of movement and the Knee injury and Osteoarthritis Outcome Score (KOOS), the Musculoskeletal Tumour Society (MSTS) score, the Toronto Extremity Salvage Score (TESS) and the SF-36 questionnaire. There was recurrence in four of 14 patients treated initially by open synovectomy. Local control was achieved after a second operation in 13 of 14 (93%). Recurrence occurred in 15 of 16 patients treated initially by arthroscopic synovectomy. These patients underwent a mean of 1.8 arthroscopies (one to eight) before open synovectomy. This achieved local control in 8 of 15 (53%) after the first synovectomy and in 12 of 15 (80%) after two. The functional outcome and QOL of patients who had undergone primary arthroscopic synovectomy and its attendant subsequent surgical procedures were compared with those who had had a primary open synovectomy using the following measures: range of movement (114º versus 127º; p = 0.03); KOOS (48 versus 71; p = 0.003); MSTS (19 versus 24; p = 0.02); TESS (75 versus 86; p = 0.03); and SF-36 (62 versus 80; p = 0.01).

Those who had undergone open synovectomy needed fewer subsequent operations. Most patients who had been referred with a recurrence had undergone an initial arthroscopic synovectomy followed by multiple further synovectomies. At the final follow-up of eight years (2 to 32), these patients had impaired function and QOL compared with those who had undergone open synovectomy initially.

We conclude that the natural history of Dt-GCT in patients who are treated by arthroscopic synovectomy has an unfavourable outcome, and that primary open synovectomy should be undertaken to prevent recurrence or residual disease.

Cite this article: Bone Joint J 2014; 96-B:1111–18.

We present the case of a 15-year-old boy with symptoms due to Klippel–Feil syndrome. Radiographs and CT scans demonstrated basilar impression, occipitalisation of C1 and fusion of C2/C3. MRI showed ventral compression of the medullocervical junction. Skull traction was undertaken pre-operatively to determine whether the basilar impression could be safely reduced. During traction, the C3/C4 junction migrated 12 mm caudally and spasticity resolved. Peri-operative skull-femoral traction enabled posterior occipitocervical fixation without decompression. Following surgery, cervical alignment was restored and spasticity remained absent. One year after surgery he was not limited in his activities. The surgical strategy for patients with basilar impression and congenital anomalies remains controversial. The anterior approach with decompression is often recommended for patients with ventral compression of the medullocervical region, but such procedures are technically demanding and carry a significant risk of complications. Our surgical strategy was an alternative solution. Prior to a posterior cervical fixation, without decompression, skull traction was used to confirm that the deformity was reducible and effective in resolving associated myelopathy.

Surgical decision-making in lumbar spinal stenosis involves assessment of clinical parameters and the severity of the radiological stenosis. We suspected that surgeons based surgical decisions more on dural sac cross-sectional area (DSCA) than on the morphology of the dural sac. We carried out a survey among members of three European spine societies. The axial T2-weighted MR images from ten patients with varying degrees of DSCA and morphological grades according to the recently described morphological classification of lumbar spinal stenosis, with DSCA values disclosed in half the assessed images, were used for evaluation. We provided a clinical scenario to accompany the images, which were shown to 142 responding physicians, mainly orthopaedic surgeons but also some neurosurgeons and others directly involved in treating patients with spinal disorders. As the primary outcome we used the number of respondents who would proceed to surgery for a given DSCA or morphological grade. Substantial agreement among the respondents was observed, with severe or extreme stenosis as defined by the morphological grade leading to surgery. This decision was not dependent on the number of years in practice, medical density or specialty. Disclosing the DSCA did not alter operative decision-making. In all, 40 respondents (29%) had prior knowledge of the morphological grading system, but their responses showed no difference from those who had not. This study suggests that the participants were less influenced by DSCA than by the morphological appearance of the dural sac.

Classifying lumbar spinal stenosis according to morphology rather than surface measurements appears to be consistent with current clinical practice.

Cartilage repair in terms of replacement, or regeneration of damaged or diseased articular cartilage with functional tissue, is the ‘holy grail’ of joint surgery. A wide spectrum of strategies for cartilage repair currently exists and several of these techniques have been reported to be associated with successful clinical outcomes for appropriately selected indications. However, based on respective advantages, disadvantages, and limitations, no single strategy, or even combination of strategies, provides surgeons with viable options for attaining successful long-term outcomes in the majority of patients. As such, development of novel techniques and optimisation of current techniques need to be, and are, the focus of a great deal of research from the basic science level to clinical trials. Translational research that bridges scientific discoveries to clinical application involves the use of animal models in order to assess safety and efficacy for regulatory approval for human use. This review article provides an overview of animal models for cartilage repair.

Cite this article: Bone Joint Res 2014;4:89–94.

High-pressure injection injuries occur infrequently but are usually work-related and involve the non-dominant hand. The neck is a very rare site for such an injury. We describe the management of a 36-year-old man with a high-pressure grease-gun injection injury to his neck causing a cervical spinal cord injury. He developed severe motor and sensory changes which were relieved by surgical removal of the grease through anterior and posterior approaches.

We have previously reported the short-term radiological results of a randomised controlled trial comparing kinematically aligned total knee replacement (TKR) and mechanically aligned TKR, along with early pain and function scores. In this study we report the two-year clinical results from this trial. A total of 88 patients (88 knees) were randomly allocated to undergo either kinematically aligned TKR using patient-specific guides, or mechanically aligned TKR using conventional instruments. They were analysed on an intention-to-treat basis. The patients and the clinical evaluator were blinded to the method of alignment.

At a minimum of two years, all outcomes were better for the kinematically aligned group, as determined by the mean Oxford knee score (40 (15 to 48) versus 33 (13 to 48); p = 0.005), the mean Western Ontario McMaster Universities Arthritis index (WOMAC) (15 (0 to 63) versus 26 (0 to 73); p = 0.005), mean combined Knee Society score (160 (93 to 200) versus 137 (64 to 200); p= 0.005) and mean flexion of 121° (100 to 150) versus 113° (80 to 130) (p = 0.002). The odds ratio of having a pain-free knee at two years with the kinematically aligned technique (Oxford and WOMAC pain scores) was 3.2 (p = 0.020) and 4.9 (p = 0.001), respectively, compared with the mechanically aligned technique. Patients in the kinematically aligned group walked a mean of 50 feet further in hospital prior to discharge compared with the mechanically aligned group (p = 0.044).

In this study, the use of a kinematic alignment technique performed with patient-specific guides provided better pain relief and restored better function and range of movement than the mechanical alignment technique performed with conventional instruments.

Cite this article: Bone Joint J 2014;96-B:907–13.

While the Cochrane Collaboration have been busy over the last four months, only a handful of their published reviews have been of any relevance to orthopaedic and trauma surgeons. Those that are provide the reader with an overview of work on imaging modalities, antibiotic therapy, changes to the surgical site dressing and practices surrounding post-operative wound management, including post-op bathing and negative pressure wound therapy for use in the treatment of diabetic foot wounds.

Inherent disadvantages of reverse shoulder arthroplasty designs based on the Grammont concept have raised a renewed interest in less-medialised designs and techniques. The aim of this study was to evaluate the outcome of reverse shoulder arthroplasty (RSA) with the fully-constrained, less-medialised, Bayley–Walker prosthesis performed for the treatment of rotator-cuff-deficient shoulders with glenohumeral arthritis. A total of 97 arthroplasties in 92 patients (53 women and 44 men, mean age 67 years (standard deviation (sd) 10, (49 to 85)) were retrospectively reviewed at a mean follow-up of 50 months ((sd 25) (24 to 96)). The mean Oxford shoulder score and subjective shoulder value improved from 47 (sd 9) and 24 points (sd 18) respectively before surgery to 28 (sd 11) and 61 (sd 24) points after surgery (p <  0.001). The mean pain at rest decreased from 5.3 (sd 2.8) to 1.5 (sd 2.3) (p < 0.001). The mean active forward elevation and external rotation increased from 42^°(sd 30) and 9^° (sd 15) respectively pre-operatively to 78^° (sd 39) and 24^° (sd 17) post-operatively (p < 0.001). A total of 20 patients required further surgery for complications; 13 required revision of components. No patient developed scapular notching.

The Bayley–Walker prosthesis provides reliable pain relief and reasonable functional improvement for patients with symptomatic cuff-deficient shoulders. Compared with other designs of RSA, it offers a modest improvement in forward elevation, but restores external rotation to some extent and prevents scapular notching. A longer follow-up is required to assess the survival of the prosthesis and the clinical performance over time.

Cite this article: Bone Joint J 2014;96-B:936–42.

We retrospectively assessed the value of identifying impinging osteophytes using dynamic computer simulation of CT scans of the elbow in assisting their arthroscopic removal in patients with osteoarthritis of the elbow. A total of 20 patients were treated (19 men and one woman, mean age 38 years (19 to 55)) and followed for a mean of 25 months (24 to 29). We located the impinging osteophytes dynamically using computerised three-dimensional models of the elbow based on CT data in three positions of flexion of the elbow. These were then removed arthroscopically and a capsular release was performed.

The mean loss of extension improved from 23° (10° to 45°) pre-operatively to 9° (0° to 25°) post-operatively, and the mean flexion improved from 121° (80° to 140°) pre-operatively to 130° (110° to 145°) post-operatively. The mean Mayo Elbow Performance Score improved from 62 (30 to 85) to 95 (70 to 100) post-operatively. All patients had pain in the elbow pre-operatively which disappeared or decreased post-operatively. According to their Mayo scores, 14 patients had an excellent clinical outcome and six a good outcome; 15 were very satisfied and five were satisfied with their post-operative outcome.

We recommend this technique in the surgical management of patients with osteoarthritis of the elbow.

Cite this article: Bone Joint J 2014;96-B:237–41.

The February 2014 Shoulder & Elbow Roundup³⁶⁰ looks at: whether arthroscopic acromioplasty is a cost-effective intervention; shockwave therapy in cuff tear; whether microfracture relieves short-term pain in cuff repair; the promising early results from L-PRF augmented cuff repairs; rehabilitation following cuff repair; supination strength following biceps tendon rupture; whether longer is better in humeral components; fatty degeneration in a rodent model; and the controversial acromioclavicular joint dislocation.