We have investigated the benefits of patient specific instrument guides, applied to osteotomies around the knee. Single, dual and triple planar osteotomies were performed on tibias or femurs in 14 subjects. In all patients, a detailed pre-operative plan was prepared based upon full leg standing radiographic and CT scan information. The planned level of the osteotomy and open wedge resection was relayed to the surgery by virtue of a patient specific guide developed from the images. The mean deviation between the planned wedge angle and the executed wedge angle was 0° (-1 to 1, sd 0.71) in the coronal plane and 0.3° (-0.9 to 3, sd 1.14) in the sagittal plane. The mean deviation between the planned hip, knee, ankle angle (HKA) on full leg standing radiograph and the post-operative HKA was 0.3° (-1 to 2, sd 0.75). It is concluded that this is a feasible and valuable concept from the standpoint of pre-operative software based planning, surgical application and geometrical accuracy of outcome.

Cite this article: Bone Joint J 2013;95-B, Supple A:153–8.

The biomechanics of the patellofemoral joint can become disturbed during total knee replacement by alterations induced by the position and shape of the different prosthetic components. The role of the patella and femoral trochlea has been well studied. We have examined the effect of anterior or posterior positioning of the tibial component on the mechanisms of patellofemoral contact in total knee replacement. The hypothesis was that placing the tibial component more posteriorly would reduce patellofemoral contact stress while providing a more efficient lever arm during extension of the knee.

We studied five different positions of the tibial component using a six degrees of freedom dynamic knee simulator system based on the Oxford rig, while simulating an active knee squat under physiological loading conditions. The patellofemoral contact force decreased at a mean of 2.2% for every millimetre of posterior translation of the tibial component. Anterior positions of the tibial component were associated with elevation of the patellofemoral joint pressure, which was particularly marked in flexion > 90°.

From our results we believe that more posterior positioning of the tibial component in total knee replacement would be beneficial to the patellofemoral joint.

We developed the Oxford ankle foot questionnaire to assess the disability associated with foot and ankle problems in children aged from five to 16 years. A survey of 158 children and their parents was carried out to determine the content, scaling, reliability and validity of the instrument. Scores from the questionnaire can be calculated to measure the effect of foot or ankle problems on three domains of children’s lives: physical, school and play, and emotional. Scores for each domain were shown to be internally consistent, stable, and to vary little whether reported by child or parent. Satisfactory face, content and construct validity were demonstrated. The questionnaire is appropriate for children with a range of conditions and can provide clinically useful information to supplement other assessment methods. We are currently carrying out further work to assess the responsiveness of questionnaire scores to change over time and with treatment.

Recent reports have suggested an increase in the number of anterior cruciate ligament (ACL) injuries in children, although their true incidence is unknown.

The prognosis of the ACL-deficient knee in young active individuals is poor because of secondary meniscal tears, persistent instability and early-onset osteoarthritis. The aim of surgical reconstruction is to provide stability while avoiding physeal injury. Techniques of reconstruction include transphyseal, extraphyseal or partial physeal sparing procedures.

In this paper we review the management of ACL tears in skeletally immature patients.

Cite this article: Bone Joint J 2013;95-B:1562–9.

Although much has been published on the causes of slipped upper femoral epiphysis and the results of treatment, little attention has been given to the mechanism of the slip. This study presents the results of the analysis of 13 adolescent femora, and the attempts to reproduce the radiological appearances of a typical slip. The mean age of the skeletons was 13 years (11 to 15). It was found that the internal bony architecture in the zone of the growth plate was such that a slip of the epiphysis on the metaphysis (in the normal meaning of the word slip) could not take place, largely relating to the presence of a tubercle of bone projecting down from the epiphysis. The only way that the appearance of a typical slipped upper femoral epiphysis could be reproduced was by rotating the epiphysis posteromedially on the metaphysis. The presence and size of this peg-like tubercle was shown radiologically by CT scanning in one pair of intact adolescent femurs.

We describe the routine imaging practices of Level 1 trauma centres for patients with severe pelvic ring fractures, and the interobserver reliability of the classification systems of these fractures using plain radiographs and three-dimensional (3D) CT reconstructions. Clinical and imaging data for 187 adult patients (139 men and 48 women, mean age 43 years (15 to 101)) with a severe pelvic ring fracture managed at two Level 1 trauma centres between July 2007 and June 2010 were extracted. Three experienced orthopaedic surgeons classified the plain radiographs and 3D CT reconstruction images of 100 patients using the Tile/AO and Young–Burgess systems. Reliability was compared using kappa statistics. A total of 115 patients (62%) had plain radiographs as well as two-dimensional (2D) CT and 3D CT reconstructions, 52 patients (28%) had plain films only, 12 (6.4%) had 2D and 3D CT reconstructions images only, and eight patients (4.3%) had no available images. The plain radiograph was limited to an anteroposterior pelvic view. Patients without imaging, or only plain films, were more severely injured. A total of 72 patients (39%) were imaged with a pelvic binder in situ.

Interobserver reliability for the Tile/AO (Kappa 0.10 to 0.17) and Young–Burgess (Kappa 0.09 to 0.21) was low, and insufficient for clinical and research purposes.

Severe pelvic ring fractures are difficult to classify due to their complexity, the increasing use of early treatment such as with pelvic binders, and the absence of imaging altogether in important patient sub-groups, such as those who die early of their injuries.

Cite this article: Bone Joint J 2013;95-B:1396–1401.

We hypothesised that a large acromial cover with an upwardly tilted glenoid fossa would be associated with degenerative rotator cuff tears (RCTs), and conversely, that a short acromion with an inferiorly inclined glenoid would be associated with glenohumeral osteoarthritis (OA). This hypothesis was tested using a new radiological parameter, the critical shoulder angle (CSA), which combines the measurements of inclination of the glenoid and the lateral extension of the acromion (the acromion index).

The CSA was measured on standardised radiographs of three groups: 1) a control group of 94 asymptomatic shoulders with normal rotator cuffs and no OA; 2) a group of 102 shoulders with MRI-documented full-thickness RCTs without OA; and 3) a group of 102 shoulders with primary OA and no RCTs noted during total shoulder replacement. The mean CSA was 33.1° (26.8° to 38.6°) in the control group, 38.0° (29.5° to 43.5°) in the RCT group and 28.1° (18.6° to 35.8°) in the OA group. Of patients with a CSA > 35°, 84% were in the RCT group and of those with a CSA < 30°, 93% were in the OA group.

We therefore concluded that primary glenohumeral OA is associated with significantly smaller degenerative RCTs with significantly larger CSAs than asymptomatic shoulders without these pathologies. These findings suggest that individual quantitative anatomy may imply biomechanics that are likely to induce specific types of degenerative joint disorders.

Cite this article: Bone Joint J 2013;95-B:935–41.

We present the development and results of a nationwide, prospective, observational follow-up programme including patient-reported outcome measures (PROMs) for the Swedish Hip Arthroplasty Register. The programme started in 2002 and has gradually expanded to include all units performing total hip replacement in Sweden. The self-administered PROMs protocol comprises the EQ-5D instrument, the Charnley class categorisation and visual analogue scales for pain and satisfaction. These current analyses include 34 960 total hip replacements with complete pre- and one-year post-operative questionnaires.

Patients eligible for total hip replacement generally report low health-related quality of life and suffer from pain. One year post-operatively the mean EQ-5D index increased to above the level of an age- and gender-matched population, with a considerable reduction of pain (p < 0.001). Females, younger patients and those with Charnley category C reported a lower EQ-5D index pre-operatively than males, older patients and Charnley category A or B, respectively (all p < 0.001). In a multivariable regression analysis Charnley category C, male gender and higher age were associated with less improvement in health-related quality of life (p < 0.001).

Nationwide implementation of a PROMs programme requires a structured organisation and effective data capture. Patients’ response rates to the Registry are good. The continuous collection of PROMs permits local and national improvement work and allows for further health-economic evaluation.

The Exeter femoral stem is a double-tapered highly polished collarless cemented implant with good long-term clinical results. In order to determine why the stem functions well we have undertaken a long-term radiostereometric analysis (RSA) study.

A total of 20 patients undergoing primary Exeter total hip replacement for osteoarthritis using the Hardinge approach were recruited and followed with RSA for ten years. The stems progressively subsided and internally rotated with posterior head migration. The mean subsidence was 0.7 mm (95% confidence interval (CI) 0.5 to 0.9) at two years and 1.3 mm (95% CI 1.0 to 1.6) at ten years. The mean posterior migration of the head was 0.7 mm (95% CI 0.5 to 0.9) at two years and 1.2 mm (95% CI 1.0 to 1.4) at ten years. There was no significant cement restrictor migration.

The Exeter stem continues to subside slowly into the cement mantle in the long term. This appears to compress the cement and the cement bone interface, contributing to secure fixation in the long term.

Cite this article: Bone Joint J 2013;95-B:605–8.

We hypothesised that the use of computer navigation-assisted surgery for pelvic and sacral tumours would reduce the risk of an intralesional margin. We reviewed 31 patients (18 men and 13 women) with a mean age of 52.9 years (13.5 to 77.2) in whom computer navigation-assisted surgery had been carried out for a bone tumour of the pelvis or sacrum. There were 23 primary malignant bone tumours, four metastatic tumours and four locally advanced primary tumours of the rectum. The registration error when using computer navigation was <  1 mm in each case. There were no complications related to the navigation, which allowed the preservation of sacral nerve roots (n = 13), resection of otherwise inoperable disease (n = 4) and the avoidance of hindquarter amputation (n = 3). The intralesional resection rate for primary tumours of the pelvis and sacrum was 8.7% (n = 2): clear bone resection margins were achieved in all cases. At a mean follow-up of 13.1 months (3 to 34) three patients (13%) had developed a local recurrence. The mean time alive from diagnosis was 16.8 months (4 to 48).

Computer navigation-assisted surgery is safe and has reduced our intralesional resection rate for primary tumours of the pelvis and sacrum. We recommend this technique as being worthy of further consideration for this group of patients.

Cite this article: Bone Joint J 2013;95-B:1417–24.

Whether to combine spinal decompression with fusion in patients with symptomatic lumbar spinal stenosis remains controversial. We performed a cohort study to determine the effect of the addition of fusion in terms of patient satisfaction after decompressive spinal surgery in patients with and without a degenerative spondylolisthesis.

The National Swedish Register for Spine Surgery (Swespine) was used for the study. Data were obtained for all patients in the register who underwent surgery for stenosis on one or two adjacent lumbar levels. A total of 5390 patients fulfilled the inclusion criteria and completed a two-year follow-up. Using multivariable models the results of 4259 patients who underwent decompression alone were compared with those of 1131 who underwent decompression and fusion. The consequence of having an associated spondylolisthesis in the operated segments pre-operatively was also considered.

At two years there was no significant difference in patient satisfaction between the two treatment groups for any of the outcome measures, regardless of the presence of a pre-operative spondylolisthesis. Moreover, the proportion of patients who required subsequent further lumbar surgery was also similar in the two groups.

In this large cohort the addition of fusion to decompression was not associated with an improved outcome.

Cite this article: Bone Joint J 2013;95-B:960–5.

We undertook a study on eight arms from fresh cadavers to define the clinical usefulness of the lesser sigmoid notch as a landmark when reconstructing the length of the neck of the radius in replacement of the head with a prosthesis. The head was resected and its height measured, along with several control measurements. This was compared with in situ measurements from the stump of the neck to the proximal edge of the lesser sigmoid notch of the ulna. All the measurements were performed three times by three observers acting independently.

The results were highly reproducible with intra- and interclass correlations of > 0.99. The mean difference between the measurement on the excised head and the distance from the stump of the neck and the lesser sigmoid notch was −0.02 mm (−1.24 to +0.97). This difference was not statistically significant (p = 0.78).

The proximal edge of the lesser sigmoid notch provides a reliable landmark for positioning a replacement of the radial head and may have clinical application.

We compared 55 consecutive total hip replacements performed on 53 morbidly obese patients with osteoarthritis with a matched group of 55 total hip replacements in 53 non-obese patients. The groups were matched for age, gender, prosthesis type, laterality and preoperative Harris Hip Score. They were followed prospectively for five years and the outcomes were assessed using the Harris Hip Score, the Short-form 36 score and radiological findings.

Survival at five years using revision surgery as an endpoint, was 90.9% (95% confidence interval 82.9 to 98.9) for the morbidly obese and 100% for the non-obese patients. The Harris Hip and the Short-form 36 scores were significantly better in the non-obese group (p < 0.001). The morbidly obese patients had a higher rate of complications (22% vs 5%, p = 0.012), which included dislocation and both superficial and deep infection.

In light of these inferior results, morbidly obese patients should be advised to lose weight before undergoing a total hip replacement, and counselled regarding the complications. Despite these poorer results, however, the patients have improved function and quality of life.

Latissimus dorsi tendon transfer (LDTT) is technically challenging. In order to clarify the local structural anatomy, we undertook a morphometric study using six complete cadavers (12 shoulders). Measurements were made from the tendon to the nearby neurovascular structures with the arm in two positions: flexed and internally rotated, and adducted in neutral rotation. The tendon was then transferred and measurements were taken from the edge of the tendon to a reference point on the humeral head in order to assess the effect of a novel two-stage release on the excursion of the tendon.

With the shoulder flexed and internally rotated, the mean distances between the superior tendon edge and the radial nerve, brachial artery, axillary nerve and posterior circumflex artery were 30 mm (26 to 34), 28 mm (17 to 39), 21 mm (12 to 28) and 15 mm (10 to 21), respectively. The mean distance between the inferior tendon edge and the radial nerve, brachial artery and profunda brachii artery was 18 mm (8 to 27), 22 mm (15 to 32) and 14 mm (7 to 21), respectively. Moving the arm to a neutral position reduced these distances. A mean of 15 mm (8 to 21) was gained from a standard soft-tissue release, and 32 mm (20 to 45) from an extensile release.

These figures help to define further the structural anatomy of this region and the potential for transfer of the latissimus dorsi tendon.

Cite this article: Bone Joint J 2013;95-B:517–22.

Revision surgery of the hip was performed on 114 hips using an extensively porous-coated femoral component. Of these, 95 hips (94 patients) had a mean follow-up of 10.2 years (5 to 17). No cortical struts were used and the cortical index and the femoral cortical width were measured at different levels.

There were two revisions for aseptic loosening. Survivorship at 12 years for all causes of failure was 96.9% (95% confidence interval 93.5 to 100) in the best-case scenario. Fibrous or unstable fixation was associated with major bone defects. The cortical index (p = 0.045) and the lateral cortical thickness (p = 0.008) decreased at the proximal level over time while the medial cortex increased (p = 0.001) at the proximal and distal levels. An increase in the proximal medial cortex was found in patients with an extended transtrochanteric osteotomy (p = 0.026) and in those with components shorter than 25 cm (p = 0.008).

The use of the extensively porous-coated femoral component can provide a solution for difficult cases in revision surgery. Radiological bony ingrowth is common. Although without clinical relevance at the end of follow-up, the thickness of the medial femoral cortex often increased while that of the lateral cortex decreased. In cases in which a shorter component was used and in those undertaken using an extended trochanteric osteotomy, there was a greater increase in thickness of the femoral cortex over time.

We investigated whether an asymmetric extension gap seen on routine post-operative radiographs after primary total knee replacement (TKR) is associated with pain at three, six, 12 and 24 months’ follow-up. On radiographs of 277 patients after primary TKR we measured the distance between the tibial tray and the femoral condyle on both the medial and lateral sides. A difference was defined as an asymmetric extension gap. We considered three groups (no asymmetric gap, medial-opening and lateral-opening gap) and calculated the associations with the Western Ontario and McMaster Universities osteoarthritis index pain scores over time.

Those with an asymmetric extension gap of ≥ 1.5 mm had a significant association with pain scores at three months’ follow-up; patients with a medial-opening extension gap reported more pain and patients with a lateral-opening extension gap reported less pain (p = 0.036). This effect was still significant at six months (p = 0.044), but had lost significance by 12 months (p = 0.924). When adjusting for multiple cofounders the improvement in pain was more pronounced in patients with a lateral-opening extension gap than in those with a medial-opening extension gap at three (p = 0.037) and six months’ (p = 0.027) follow-up.

Cite this article: Bone Joint J 2013;95-B:472–7.

The Morscher-Spotorno (MS-30) femoral stem is a stainless-steel, straight, three-dimensionally tapered, collarless implant for cemented fixation in total hip replacement.

We report the results at ten years of a consecutive series of 124 total hip replacements in 121 patients with the matt-surfaced MS-30 stem and an alumina ceramic head of 28-mm diameter. All the stems were fixed with Palacos bone cement with gentamicin using a modern cementing technique. They were combined with an uncemented, press-fit cup. The mean period of observation was 10.2 years (8.3 to 12.1) and no patient was lost to follow-up. Twenty-seven patients (22%) died with the implant in situ. Nine could only be interviewed by telephone. We included 85 patients with 88 hips in the clinical and radiological follow-up examinations.

None of the stems or cups had been revised. The Harris hip score was excellent or good in 97% (85 hips) and moderate in 3% (three hips). Radiologically, six hips (6.8%) had osteolysis adjacent to the stem, mostly in Gruen zone 7. Twenty (22.7%) showed one or more radiolucent lines. Twenty-two stems (25%) had subsided by 2 mm to 5 mm. In these cases two showed osteolysis (9.1%) with subsidence and four without (6.1%). Radiolucent lines were seen in seven with migration (31.8%) and in 13 without (19.7%). No infections and no acetabular osteolysis were observed.

The clinical results were excellent with survivorship after ten years of 100% and only a slightly statistically non-significant higher rate of osteolysis and radiolucency in cases of subsidence.

The survivorship of contemporary resurfacing arthroplasty of the hip using metal-on-metal bearings is better than that of first generation designs, but short-term failures still occur. The most common reasons for failure are fracture of the femoral neck, loosening of the component, osteonecrosis of the femoral head, reaction to metal debris and malpositioning of the component. In 2008 the Australian National Joint Registry reported an inverse relationship between the size of the head component and the risk of revision in resurfacing hip arthroplasty. Hips with a femoral component size of ≤ 44 mm have a fivefold increased risk of revision than those with femoral components of ≥ 55 mm irrespective of gender. We have reviewed the literature to explore this observation and to identify possible reasons including the design of the implant, loading of the femoral neck, the orientation of the component, the production of wear debris and the effects of metal ions, penetration of cement and vascularity of the femoral head. Our conclusion is that although multifactorial, the most important contributors to failure in resurfacing arthroplasty of the hip are likely to be the design and geometry of the component and the orientation of the acetabular component.

This study validates the short-form WOMAC function scale for assessment of conservative treatment of osteoarthritis of the knee. Data were collected before treatment and six and nine months later, from 100 patients with osteoarthritis of the knee to determine the validity, internal consistency, test-retest reliability, floor and ceiling effects, and responsiveness of the short-form WOMAC function scale. The scale showed high correlation with the traditional WOMAC and other measures. The internal consistency was good (Cronbach α: 0.88 to 0.95) and an excellent test-retest reliability was found (Lin’s concordance correlation coefficient (ρ_c): 0.85 to 0.94). The responsiveness was adequate and comparable to that of the traditional WOMAC (standardised response mean 0.56 to 0.44 and effect size 0.64 to 0.57) and appeared not to be significantly affected by floor or ceiling effects (0% and 7%, respectively).

The short-form WOMAC function scale is a valid, reliable and responsive alternative to the traditional WOMAC in the evaluation of patients with osteoarthritis of the knee managed conservatively. It is simple to use in daily practice and is therefore less of a burden for patients in clinical trials.