There is an increased risk of fracture following osteoplasty of the femoral neck for cam-type femoroacetabular impingement (FAI). Resection of up to 30% of the anterolateral head–neck junction has previously been considered to be safe, however, iatrogenic fractures have been reported with resections within these limits. We re-evaluated the amount of safe resection at the anterolateral femoral head–neck junction using a biomechanically consistent model.

In total, 28 composite bones were studied in four groups: control, 10% resection, 20% resection and 30% resection. An axial load was applied to the adducted and flexed femur. Peak load, deflection at time of fracture and energy to fracture were assessed using comparison groups.

There was a marked difference in the mean peak load to fracture between the control group and the 10% resection group (p < 0.001). The control group also tolerated significantly more deflection before failure (p < 0.04). The mean peak load (p = 0.172), deflection (p = 0.547), and energy to fracture (p = 0.306) did not differ significantly between the 10%, 20%, and 30% resection groups.

Any resection of the anterolateral quadrant of the femoral head–neck junction for FAI significantly reduces the load-bearing capacity of the proximal femur. After initial resection of cortical bone, there is no further relevant loss of stability regardless of the amount of trabecular bone resected.

Based on our findings we recommend any patients who undergo anterolateral femoral head–neck junction osteoplasty should be advised to modify their post-operative routine until cortical remodelling occurs to minimise the subsequent fracture risk.

Cite this article: Bone Joint J 2015;97-B:1214–19.

Objective

Hip arthroscopy in the setting of hip dysplasia is controversial in the orthopaedic community, as the outcome literature has been variable and inconclusive. We hypothesise that outcomes of hip arthroscopy may be diminished in the setting of hip dysplasia, but outcomes may be acceptable in milder or borderline cases of hip dysplasia.

This study investigates and defines the topographic anatomy of the medial femoral circumflex artery (MFCA) terminal branches supplying the femoral head (FH). Gross dissection of 14 fresh–frozen cadaveric hips was undertaken to determine the extra and intracapsular course of the MFCA’s terminal branches. A constant branch arising from the transverse MFCA (inferior retinacular artery; IRA) penetrates the capsule at the level of the anteroinferior neck, then courses obliquely within the fibrous prolongation of the capsule wall (inferior retinacula of Weitbrecht), elevated from the neck, to the posteroinferior femoral head–neck junction. This vessel has a mean of five (three to nine) terminal branches, of which the majority penetrate posteriorly. Branches from the ascending MFCA entered the femoral capsular attachment posteriorly, running deep to the synovium, through the neck, and terminating in two branches. The deep MFCA penetrates the posterosuperior femoral capsular. Once intracapsular, it divides into a mean of six (four to nine) terminal branches running deep to the synovium, within the superior retinacula of Weitbrecht of which 80% are posterior. Our study defines the exact anatomical location of the vessels, arising from the MFCA and supplying the FH. The IRA is in an elevated position from the femoral neck and may be protected from injury during fracture of the femoral neck. We present vascular ‘danger zones’ that may help avoid iatrogenic vascular injury during surgical interventions about the hip.

Cite this article: Bone Joint J 2015;97-B:1204–13.

Aims

The aim of this study is to introduce and investigate the efficacy and feasibility of a new vertebral osteotomy technique, vertebral column decancellation (VCD), for rigid thoracolumbar kyphotic deformity (TLKD) secondary to ankylosing spondylitis (AS).

Pathological assessment of periprosthetic tissues is important, not only for diagnosis, but also for understanding the pathobiology of implant failure. The host response to wear particle deposition in periprosthetic tissues is characterised by cell and tissue injury, and a reparative and inflammatory response in which there is an innate and adaptive immune response to the material components of implant wear. Physical and chemical characteristics of implant wear influence the nature of the response in periprosthetic tissues and account for the development of particular complications that lead to implant failure, such as osteolysis which leads to aseptic loosening, and soft-tissue necrosis/inflammation, which can result in pseudotumour formation. The innate response involves phagocytosis of implant-derived wear particles by macrophages; this is determined by pattern recognition receptors and results in expression of cytokines, chemokines and growth factors promoting inflammation and osteoclastogenesis; phagocytosed particles can also be cytotoxic and cause cell and tissue necrosis. The adaptive immune response to wear debris is characterised by the presence of lymphoid cells and most likely occurs as a result of a cell-mediated hypersensitivity reaction to cell and tissue components altered by interaction with the material components of particulate wear, particularly metal ions released from cobalt-chrome wear particles.

Cite this article: Professor N. A. Athanasou. The pathobiology and pathology of aseptic implant failure. Bone Joint Res 2016;5:162–168. DOI: 10.1302/2046-3758.55.BJR-2016-0086.

In this paper we propose a new classification of neurogenic peri-articular heterotopic ossification (HO) of the hip based on three-dimensional (3D) CT, with the aim of improving pre-operative planning for its excision.

A total of 55 patients (73 hips) with clinically significant HO after either traumatic brain or spinal cord injury were assessed by 3D-CT scanning, and the results compared with the intra-operative findings.

At operation, the gross pathological anatomy of the HO as identified by 3D-CT imaging was confirmed as affecting the peri-articular hip muscles to a greater or lesser extent. We identified seven patterns of involvement: four basic (anterior, medial, posterior and lateral) and three mixed (anteromedial, posterolateral and circumferential). Excellent intra- and inter-observer agreement, with kappa values > 0.8, confirmed the reproducibility of the classification system.

We describe the different surgical approaches used to excise the HO which were guided by the 3D-CT findings. Resection was always successful.

3D-CT imaging, complemented in some cases by angiography, allows the surgeon to define the 3D anatomy of the HO accurately and to plan its surgical excision with precision.

Cite this article: Bone Joint J 2015; 97-B:899–904.

The aim of this study was to define return to theatre (RTT) rates for elective hip and knee replacement (HR and KR), to describe the predictors and to show the variations in risk-adjusted rates by surgical team and hospital using national English hospital administrative data.

We examined information on 260 206 HRs and 315 249 KRs undertaken between April 2007 and March 2012. The 90-day RTT rates were 2.1% for HR and 1.8% for KR. Male gender, obesity, diabetes and several other comorbidities were associated with higher odds for both index procedures. For HR, hip resurfacing had half the odds of cement fixation (OR = 0.58, 95% confidence intervals (CI) 0.47 to 0.71). For KR, unicondylar KR had half the odds of total replacement (OR = 0.49, 95% CI 0.42 to 0.56), and younger ages had higher odds (OR = 2.23, 95% CI 1.65 to 3.01) for ages < 40 years compared with ages 60 to 69 years). There were more funnel plot outliers at three standard deviations than would be expected if variation occurred on a random basis.

Hierarchical modelling showed that three-quarters of the variation between surgeons for HR and over half the variation between surgeons for KR are not explained by the hospital they operated at or by available patient factors. We conclude that 90-day RTT rate may be a useful quality indicator for orthopaedics.

Cite this article: Bone Joint J 2014; 96-B:1663–8.

Aims

The primary aim of this study was to investigate the effect of an enhanced recovery program (ERP) on the short-term functional outcome after total hip arthroplasty (THA). Secondary outcomes included its effect on rates of dislocation and mortality.

Aims

The optimal management of intracapsular fractures of the femoral neck in independently mobile patients remains open to debate. Successful fixation obviates the limitations of arthroplasty for this group of patients. However, with fixation failure rates as high as 30%, the outcome of revision surgery to salvage total hip arthroplasty (THA) must be considered. We carried out a systematic review to compare the outcomes of salvage THA and primary THA for intracapsular fractures of the femoral neck.

Aims

We aimed to assess the comparability of data in joint replacement registries and identify ways of improving the comparisons between registries and the overall monitoring of joint replacement surgery.

An uncemented hemispherical acetabular component is the mainstay of acetabular revision and gives excellent long-term results.

Occasionally, the degree of acetabular bone loss means that a hemispherical component will be unstable when sited in the correct anatomical location or there is minimal bleeding host bone left for biological fixation. On these occasions an alternative method of reconstruction has to be used.

A major column structural allograft has been shown to restore the deficient bone stock to some degree, but it needs to be off-loaded with a reconstruction cage to prevent collapse of the graft. The use of porous metal augments is a promising method of overcoming some of the problems associated with structural allograft. If the defect is large, the augment needs to be protected by a cage to allow ingrowth to occur. Cup-cage reconstruction is an effective method of treating chronic pelvic discontinuity and large contained or uncontained bone defects.

This paper presents the indications, surgical techniques and outcomes of various methods which use acetabular reconstruction cages for revision total hip arthroplasty.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):73–7.

Slipped capital femoral epiphysis (SCFE) may lead to symptomatic femoroacetabular impingement (FAI). We report our experience of arthroscopic treatment, including osteochondroplasty, for the sequelae of SCFE.

Data were prospectively collected on patients undergoing arthroscopy of the hip for the sequelae of SCFE between March 2007 and February 2013, including demographic data, radiological assessment of the deformity and other factors that may influence outcome, such as the presence of established avascular necrosis. Patients completed the modified Harris hip score (mHHS) and the non-arthritic hip score (NAHS) before and after surgery.

In total, 18 patients with a mean age of 19 years (13 to 42), were included in the study. All patients presented with pain in the hip and mechanical symptoms, and had evidence of FAI (cam or mixed impingement) on plain radiographs.

The patients underwent arthroscopic osteoplasty of the femoral neck. The mean follow-up was 29 months (23 to 56).

The mean mHHS and NAHS scores improved from 56.2 (27.5 to 100.1) and 52.1 (12.5 to 97.5) pre-operatively to 75.1 (33.8 to 96.8, p = 0.01) and 73.6 (18.8 to 100, p = 0.02) at final follow-up, respectively. Linear regression analysis demonstrated a significant association between poorer outcome scores and increased time to surgery following SCFE (p < 0.05 for all parameters except baseline MHHS).

Symptomatic FAI following (SCFE) may be addressed using arthroscopic techniques, and should be treated promptly to minimise progressive functional impairment and chondrolabral degeneration.

Take home message: Arthroscopy of the hip can be used to treat femoroacetabular impingement successfully following SCFE. However, this should be performed promptly after presentation in order to prevent irreversible progression and poorer clinical outcomes.

Cite this article: Bone Joint J 2016;98-B:21–7.

Aims

The authors present the results of a cohort study of 60 adult patients presenting sequentially over a period of 15 years from 1997 to 2012 to our hospital for treatment of thoracic and/or lumbar vertebral burst fractures, but without neurological deficit.

The December 2015 Children’s orthopaedics Roundup³⁶⁰ looks at: Paediatric femoral fractures: a single incision nailing?; Lateral condylar fractures: open or percutaneous?;

Forearm refracture: the risks; Tibial spine fractures; The child’s knee in MRI; The mechanics of SUFE; Idiopathic clubfoot

We describe our experience in the reduction of dislocation of the hip secondary to developmental dysplasia using ultrasound-guided gradual reduction using flexion and abduction continuous traction (FACT-R). During a period of 13 years we treated 208 Suzuki type B or C complete dislocations of the hip in 202 children with a mean age of four months (0 to 11). The mean follow-up was 9.1 years (five to 16). The rate of reduction was 99.0%. There were no recurrent dislocations, and the rate of avascular necrosis of the femoral head was 1.0%. The rate of secondary surgery for residual acetabular dysplasia was 19.2%, and this was significantly higher in those children in whom the initial treatment was delayed or if other previous treatments had failed (p = 0.00045). The duration of FACT-R was significantly longer in severe dislocations (p = 0.001) or if previous treatments had failed (p = 0.018).

This new method of treatment is effective and safe in these difficult cases and offers outcomes comparable to or better than those of standard methods.

Cite this article: Bone Joint J 2015;97-B:405–11.

The December 2015 Hip & Pelvis Roundup³⁶⁰ looks at: Vitamin E infusion helpful in polyethylene; Hip replacement in fracture and arthritis; Non-surgical treatment for arthritis; Cost and approach in hip surgery; Who does well in FAI surgery?; AAOS Thromboembolism guidelines; Thromboprophylaxis and periprosthetic joint infection; Fluid collections not limited to metal-on-metal THR

Over a 15-year prospective period, 201 infants with a clinically unstable hip at neonatal screening were subsequently reviewed in a ‘one stop’ clinic where they were assessed clinically and sonographically. Their mean age was 1.62 weeks (95% confidence interval (CI) 1.35 to 1.89). Clinical neonatal hip screening revealed a sensitivity of 62% (mean, 62.6 95%CI 50.9 to 74.3), specificity of 99.8% (mean, 99.8, 95% CI 99.7 to 99.8) and positive predictive value (PPV) of 24% (mean, 26.2, 95% CI 19.3 to 33.0). Static and dynamic sonography for Graf type IV dysplastic hips had a 15-year sensitivity of 77% (mean, 75.8 95% CI 66.9 to 84.6), specificity of 99.8% (mean, 99.8, 95% CI 99.8 to 99.8) and a PPV of 49% (mean, 55.1, 95% CI 41.6 to 68.5). There were 36 infants with an irreducible dislocation of the hip (0.57 per 1000 live births), including six that failed to resolve with neonatal splintage.

Most clinically unstable hips referred to a specialist clinic are female and stabilise spontaneously. Most irreducible dislocations are not identified from this neonatal instability group. There may be a small subgroup of females with instability of the hip which may be at risk of progression to irreducibility despite early treatment in a Pavlik harness.

A controlled study is required to assess the value of neonatal clinical screening programmes.

Cite this article: Bone Joint J 2015;97-B:265-9.

Objectives

Third-body wear is believed to be one trigger for adverse results with metal-on-metal (MOM) bearings. Impingement and subluxation may release metal particles from MOM replacements. We therefore challenged MOM bearings with relevant debris types of cobalt–chrome alloy (CoCr), titanium alloy (Ti6Al4V) and polymethylmethacrylate bone cement (PMMA).

Giant cell tumour is the most common aggressive benign tumour of the musculoskeletal system and has a high rate of local recurrence. When it occurs in proximity to the hip, reconstruction of the joint is a challenge. Options for reconstruction after wide resection include the use of a megaprosthesis or an allograft-prosthesis composite. We performed a clinical and radiological study to evaluate the functional results of a proximal femoral allograft-prosthesis composite in the treatment of proximal femoral giant cell tumour after wide resection. This was an observational study, between 2006 and 2012, of 18 patients with a mean age of 32 years (28 to 42) and a mean follow-up of 54 months (18 to 79). We achieved excellent outcomes using Harris Hip Score in 13 patients and a good outcome in five. All allografts united. There were no complications such as infection, failure, fracture or resorption of the graft, or recurrent tumour. Resection and reconstruction of giant cell tumours with proximal femoral allograft–prosthesis composite is a better option than using a prosthesis considering preservation of bone stock and excellent restoration of function.

A good result requires demanding bone banking techniques, effective measures to prevent infection and stability at the allograft-host junction.

Cite this article: Bone Joint J 2014; 96-B:1106–10.