The purpose of this study was to compare the diagnostic accuracy for the detection of infection between the culture of fluid obtained by sonication (SFC) and the culture of peri-implant tissues (PITC) in patients with early and delayed implant failure, and those with unsuspected and suspected septic failure. It was hypothesised that SFC increases the diagnostic accuracy for infection in delayed, but not early, implant failure, and in unsuspected septic failure. The diagnostic accuracy for infection of all consecutive implants (hardware or prostheses) that were removed for failure was compared between SFC and PITC. This prospective study included 317 patients with a mean age of 62.7 years (9 to 97). The sensitivity for detection of infection using SFC was higher than using PITC in an overall comparison (89.9% versus 67%, respectively; p < 0.001), in unsuspected septic failure (100% versus 48.5%, respectively; p < 0.001), and in delayed implant failure (88% versus 58%, respectively; p < 0.001). PITC sensitivity dropped significantly in unsuspected compared with suspected septic failure (p = 0.007), and in delayed compared with early failure (p = 0.013). There were no differences in specificity.

Sonication is mainly recommended when there is implant failure with no clear signs of infection and in patients with delayed implant failure. In early failure, SFC is not superior to PITC for the diagnosis of infection and, therefore, is not recommended as a routine diagnostic test in these patients.

Cite this article: Bone Joint J 2013;95-B:244–9.

We report the use of an allograft prosthetic composite for reconstruction of the skeletal defect in complex revision total hip replacement for severe proximal femoral bone loss. Between 1986 and 1999, 72 patients (20 men, 52 women) with a mean age of 59.9 years (38 to 78) underwent reconstruction using this technique.

At a mean follow-up of 12 years (8 to 20) 57 patients were alive, 14 had died and one was lost to follow-up. Further revision was performed in 19 hips at a mean of 44.5 months (11 to 153) post-operatively. Causes of failure were aseptic loosening in four, allograft resorption in three, allograft nonunion in two, allograft fracture in four, fracture of the stem in one, and deep infection in five. The survivorship of the allograft-prosthesis composite at ten years was 69.0% (95% confidence interval 67.7 to 70.3) with 26 patients remaining at risk. Survivorship was statistically significantly affected by the severity of the pre-operative bone loss (Paprosky type IV; p = 0.019), the number of previous hip revisions exceeding two (p = 0.047), and the length of the allograft used (p = 0.005).

We analysed whether a high body mass index (BMI) had a deleterious effect on outcome following autologous chondrocyte implantation (ACI) or matrix-carried autologous chondrocyte implantation (MACI) for the treatment of full-thickness chondral defects of the knee from a subset of patients enrolled in the ACI vs MACI trial at The Royal National Orthopaedic Hospital.

The mean Modified Cincinnati scores (MCS) were significantly higher (p < 0.001) post-operatively in patients who had an ideal body weight (n = 53; 20 to 24.9 kg/m²) than in overweight (n = 63; 25 to 30 kg/m²) and obese patients (n = 22; > 30 kg/m²). At a follow-up of two years, obese patients demonstrated no sustained improvement in the MCS. Patients with an ideal weight experienced significant improvements as early as six months after surgery (p = 0.007). In total, 82% of patients (31 of 38) in the ideal group had a good or excellent result, compared with 49% (22 of 45) of the overweight and 5.5% (one of 18) in the obese group (p < 0.001). There was a significant negative relationship between BMI and the MCS 24 months after surgery (r = -0.4, p = 0.001).

This study demonstrates that obese patients have worse knee function before surgery and experience no sustained benefit from ACI or MACI at two years after surgery. There was a correlation between increasing BMI and a lower MCS according to a linear regression analysis. On the basis of our findings patient selection can be more appropriately targeted.

In this paper, we consider wound healing after total knee arthroplasty.

The August 2012 Oncology Roundup³⁶⁰ looks at: prolonged symptom duration; peri-operative mortality and above-knee amputation; giant cell tumour of the spine; surgical resection for Ewing’s sarcoma; intercalary allograft reconstruction of the femur for tumour defects; and an induced membrane technique for large bone defects.

An 86-year-old male presented with a loose total hip replacement (THR) ten years after implantation. At revision for anticipated aseptic loosening, watery pus was found in the joint and Bacille-Calmette-Guérin (BCG) was seen on culture. The bacterial strain was identified and was identical to the BCG used in the intravesicular treatment of superficial bladder carcinoma in this patient ten months earlier. After revision he received a full course of antituberculous treatment.

The clinical and radiological results were excellent after follow-up for 30 months with his uncemented THR showing satisfactory incorporation. His inflammatory markers were normal and his Harris hip score was 95 points.

The diagnosis of a tuberculous infection can be easily missed, but must be considered, especially if sterile pus is encountered.

The long-term success of total knee replacement is multifactorial, including factors relating to the patient, the operation and the implant. The purpose of this study was to examine the 20-year survival of the cemented Anatomical Graduated Component (AGC) total knee replacement. Between 1983 and 2004, 7760 of these were carried out at our institution. Of these, 6726 knees which received the non-modular metal-backed tibial component with compression-moulded polyethylene and had a minimum two-year follow-up were available for study. In all, 36 knees were followed over 20 years with a survival of the tibial and femoral components together of 97.8% (95% confidence interval (CI) 0.9851 to 0.9677), with no implants being revised for polyethylene wear or osteolysis. Age > 70 was associated with increased survival (99.6%, 95% CI 99.0 to 99.8) (p < 0.0001) but pre-operative valgus alignment reduced survival (95.1%, 95% CI 90.0 to 97.6) (p = 0.0056). Age < 55 (p = 0.129), pre-operative varus alignment (p = 0.707), osteonecrosis (p = 0.06), rheumatoid arthritis (p = 0.247), and gender (p = 0.666) were not statistically associated with failure.

We attribute the success of the AGC implant to its relatively unconstrained articular geometry and the durability of a non-modular metal-backed tibial component with compression moulded polyethylene.

The April 2012 Trauma Roundup³⁶⁰ looks at fibula-pro-tibia plating, galeazzi fractures, distal radial fractures in the over 65s, transverse sacral fractures, acute dislocation of the knee, posterior malleolar fractures, immobilising the broken scaphoid, the terrible triad, lower limb amputation after trauma, and whiplash injuries

There have been few reports regarding the efficacy of posterior instrumentation alone as surgical treatment for patients with pyogenic spondylitis, thus avoiding the morbidity of anterior surgery. We report the clinical outcomes of six patients with pyogenic spondylitis treated effectively with a single-stage posterior fusion without anterior debridement at a mean follow-up of 2.8 years (2 to 5). Haematological data, including white cell count and level of C-reactive protein, returned to normal in all patients at a mean of 8.2 weeks (7 to 9) after the posterior fusion. Rigid bony fusion between the infected vertebrae was observed in five patients at a mean of 6.3 months (4.5 to 8) post-operatively, with the remaining patient having partial union. Severe back pain was immediately reduced following surgery and the activities of daily living showed a marked improvement. Methicillin-resistant Staphylococcus aureus was detected as the causative organism in four patients.

Single-stage posterior fusion may be effective in patients with pyogenic spondylitis who have relatively minor bony destruction.

We report the clinical and radiological outcome of 86 revisions of cemented hip arthroplasties using JRI-Furlong hydroxyapatite-ceramic-coated acetabular and femoral components. The acetabular component was revised in 62 hips and the femoral component in all hips. The mean follow-up was 12.6 years and no patient was lost to follow-up.

The mean age of the patients was 71.2 years. The mean Harris hip and Oxford scores were 82 (59 to 96) and 23.4 (14 to 40), respectively. The mean Charnley modification of the Merle d’Aubigné and Postel score was 5 (3 to 6) for pain, 4.9 (3 to 6) for movement and 4.4 (3 to 6) for mobility. Migration of the acetabular component was seen in two hips and the mean acetabular inclination was 42.6°. The mean linear polyethylene wear was 0.05 mm/year. The mean subsidence of the femoral component was 1.9 mm and stress shielding was seen in 23 (28%) with bony ingrowth in 76 (94%). Heterotopic ossification was seen in 12 hips (15%). There were three re-revisions, two for deep sepsis and one for recurrent dislocation and there were no re-revisions for aseptic loosening. The mean EuroQol EQ-5D description scores and health thermometer scores were 0.69 (0.51 to 0.89) and 79 (54 to 95), respectively. With an end-point of definite or probable loosening, the probability of survival at 12 years was 93.9% and 95.6% for the acetabular and femoral components, respectively. Overall survival at 12 years, with removal or further revision of either component for any reason as the end-point, was 92.3%.

Our study supports the continued use of this arthroplasty and documents the durability of hydroxyapatite-ceramic-coated components.

The June 2012 Spine Roundup³⁶⁰ looks at: back pain; spinal fusion for tuberculosis; anatomical course of the recurrent laryngeal nerve; groin pain with normal imaging; the herniated intervertebral disc; obesity’s effect on the spine; the medicolegal risks of cauda equina syndrome; and intravenous lidocaine use and failed back surgery syndrome.

The June 2012 Oncology Roundup³⁶⁰ looks at: avoiding pelvic hemipelvectomy; proximal femoral metastasis; extendible prostheses; rotationplasty; soft-tissue sarcomas; osteosarcoma of the pelvis; recurrent chondrosarcoma ; MRI and the differentiation between benign and malignant lesions; and malignant fibrous histiocytoma.

Migration of the acetabular component may give rise to oval-shaped bone defects in the acetabulum. The oblong implant is designed to fill these defects and achieve a stable cementless anchorage with no significant bone loss. We prospectively reviewed 133 oblong long oblique revision components at a mean follow-up of 9.74 years (0.6 to 14). All had been used in revisions for defects of type IIB to IIIB according to Paprosky. Aseptic loosening was the reason for revision in 11 cases (8.3%) and deep infection in seven (5.3%). The probability of implant survival over a 12-year follow-up estimated by the Kaplan-Meier method gave a survival rate of 0.85% respectively 0.90% when deep infection was excluded as the endpoint.

Our study supports the use of these components in defects from IIB to IIIA. The main precondition for success is direct contact of more than half of the surface of the implant with the host acetabular bone.

The purpose of this study was to assess the outcome of 15 patients (mean age 13.6 years (7 to 25)) with a primary sarcoma of the tibial diaphysis who had undergone excision of the affected segment that was then irradiated (90 Gy) and reimplanted with an ipsilateral vascularised fibular graft within it.

The mean follow-up was 57 months (22 to 99). The mean time to full weight-bearing was 23 weeks (9 to 57) and to complete radiological union 42.1 weeks (33 to 55). Of the 15 patients, seven required a further operation, four to obtain skin cover. The mean Musculoskeletal Society Tumor Society functional score at final follow-up was 27 out of 30 once union was complete. The functional results were comparable with those of allograft reconstruction and had a similar rate of complication.

We believe this to be a satisfactory method of biological reconstruction of the tibial diaphysis in selected patients.

Iontophoresis is a novel technique which may be used to facilitate the movement of antibiotics into the substance of bone using an electrical potential applied externally. We have examined the rate of early infection in allografts following application of this technique in clinical practice. A total of 31 patients undergoing revision arthroplasty or surgery for limb salvage received 34 iontophoresed sequential allografts, of which 26 survived for a minimum of two years. The mean serum antibiotic levels after operation were low (gentamicin 0.37 mg/l (0.2 to 0.5); flucloxacillin 1 mg/l (0 to 1) and the levels in the drains were high (gentamicin 40 mg/l (2.5 to 131); flucloxacillin 17 mg/l (1 to 43). There were no early deep infections. Two late infections were presumed to be haemotogenous; 28 of the 34 allografts were retained. In 12 patients with pre-existing proven infection further infection has not occurred at a mean follow-up of 51 months (24 to 82).

We prospectively followed 191 consecutive collarless polished tapered (CPT) femoral stems, implanted in 175 patients who had a mean age at operation of 64.5 years (21 to 85). At a mean follow-up of 15.9 years (14 to 17.5), 86 patients (95 hips) were still alive. The fate of all original stems is known. The 16-year survivorship with re-operation for any reason was 80.7% (95% confidence interval 72 to 89.4). There was no loss to follow-up, with clinical data available on all 95 hips and radiological assessment performed on 90 hips (95%). At latest follow-up, the mean Harris hip score was 78 (28 to 100) and the mean Oxford hip score was 36 (15 to 48). Stems subsided within the cement mantle, with a mean subsidence of 2.1 mm (0.4 to 19.2). Among the original cohort, only one stem (0.5%) has been revised due to aseptic loosening. In total seven stems were revised for any cause, of which four revisions were required for infection following revision of the acetabular component. A total of 21 patients (11%) required some sort of revision procedure; all except three of these resulted from failure of the acetabular component. Cemented acetabular components had a significantly lower revision burden (three hips, 2.7%) than Harris Galante uncemented components (17 hips, 21.8%) (p < 0.001).

The CPT stem continues to provide excellent radiological and clinical outcomes at 15 years following implantation. Its results are consistent with other polished tapered stem designs.

Femoral impaction bone allografting has been developed as a means of restoring bone stock in revision total hip replacement. We report the results of 75 consecutive patients (75 hips) with a mean age of 68 years (35 to 87) who underwent impaction grafting using the Exeter collarless, polished, tapered femoral stem between 1992 and 1998.

The mean follow-up period was 10.5 years (6.3 to 14.1). The median pre-operative bone defect score was 3 (interquartile range (IQR) 2 to 3) using the Endo-Klinik classification.

The median subsidence at one year post-operatively was 2 mm (IQR 1 to 3). At the final review the median Harris hip score was 80.6 (IQR 67.6 to 88.9) and the median subsidence 2 mm (IQR 1 to 4). Incorporation of the allograft into trabecular bone and secondary remodelling were noted radiologically at the final follow-up in 87% (393 of 452 zones) and 40% (181 of 452 zones), respectively.

Subsidence of the Exeter stem correlated with the pre-operative Endo-Klinik bone loss score (p = 0.037). The degree of subsidence at one year had a strong association with long-term subsidence (p < 0.001). There was a significant correlation between previous revision surgery and a poor Harris Hip score (p = 0.028), and those who had undergone previous revision surgery for infection had a higher risk of complications (p = 0.048). Survivorship at 10.5 years with any further femoral operation as the end-point was 92% (95% confidence interval 82 to 97).

There is little information about the management of peri-prosthetic fracture of the humerus after total shoulder replacement (TSR). This is a retrospective review of 22 patients who underwent a revision of their original shoulder replacement for peri-prosthetic fracture of the humerus with bone loss and/or loose components. There were 20 women and two men with a mean age of 75 years (61 to 90) and a mean follow-up 42 months (12 to 91): 16 of these had undergone a previous revision TSR. Of the 22 patients, 12 were treated with a long-stemmed humeral component that bypassed the fracture. All their fractures united after a mean of 27 weeks (13 to 94). Eight patients underwent resection of the proximal humerus with endoprosthetic replacement to the level of the fracture. Two patients were managed with a clam-shell prosthesis that retained the original components. The mean Oxford shoulder score (OSS) of the original TSRs before peri-prosthetic fracture was 33 (14 to 48). The mean OSS after revision for fracture was 25 (9 to 31). Kaplan-Meier survival using re-intervention for any reason as the endpoint was 91% (95% confidence interval (CI) 68 to 98) and 60% (95% CI 30 to 80) at one and five years, respectively.

There were two revisions for dislocation of the humeral head, one open reduction for modular humeral component dissociation, one internal fixation for nonunion, one trimming of a prominent screw and one re-cementation for aseptic loosening complicated by infection, ultimately requiring excision arthroplasty. Two patients sustained nerve palsies.

Revision TSR after a peri-prosthetic humeral fracture associated with bone loss and/or loose components is a salvage procedure that can provide a stable platform for elbow and hand function. Good rates of union can be achieved using a stem that bypasses the fracture. There is a high rate of complications and function is not as good as with the original replacement.

We describe the results of 81 consecutive revision total hip replacements with impaction grafting in 79 patients using a collared polished chrome–cobalt stem, customised in length according to the extent of distal bone loss. Our hypothesis was that the features of this stem would reduce the rate of femoral fracture and subsidence of the stem.

The mean follow-up was 12 years (8 to 15). No intra-operative fracture or significant subsidence occurred. Only one patient suffered a post-operative diaphyseal fracture, which was associated with a fall. All but one femur showed incorporation of the graft. No revision for aseptic loosening was recorded.

The rate of survival of the femoral component at 12 years, using further femoral revision as the endpoint, was 100% (95% confidence interval (CI) 95.9 to 100), and at nine years using re-operation for any reason as the endpoint, was 94.6% (95% CI 92.0 to 97.2).

These results suggest that a customised cemented polished stem individually adapted to the extent of bone loss and with a collar may reduce subsidence and the rate of fracture while maintaining the durability of the fixation.

The treatment of substantial proximal femoral bone loss in young patients with developmental dysplasia of the hip (DDH) is challenging. We retrospectively analysed the outcome of 28 patients (30 hips) with DDH who underwent revision total hip replacement (THR) in the presence of a deficient proximal femur, which was reconstructed with an allograft prosthetic composite. The mean follow-up was 15 years (8.5 to 25.5). The mean number of previous THRs was three (1 to 8). The mean age at primary THR and at the index reconstruction was 41 years (18 to 61) and 58.1 years (32 to 72), respectively. The indication for revision included mechanical loosening in 24 hips, infection in three and peri-prosthetic fracture in three.

Six patients required removal and replacement of the allograft prosthetic composite, five for mechanical loosening and one for infection. The survivorship at ten, 15 and 20 years was 93% (95% confidence interval (CI) 91 to 100), 75.5% (95% CI 60 to 95) and 75.5% (95% CI 60 to 95), respectively, with 25, eight, and four patients at risk, respectively. Additionally, two junctional nonunions between the allograft and host femur required bone grafting and plating.

An allograft prosthetic composite affords a good long-term outcome in the management of proximal femoral bone loss in revision THR in patients with DDH, while preserving distal host bone.