Hip precautions following total hip arthroplasty (THA) limits flexion, adduction and internal rotation, yet these precautions cause unnecessary psychological stress. This study aims to assess bony and implant impingement using virtual models from actual patient's bony morphology and spinopelvic parameters to deduce whether hip precautions are necessary with precise implant positioning in the Asian population.

Individualized sitting and standing sacral slope data of robotic THAs performed at two tertiary referral centers in Hong Kong was inputted into the simulation system based on patients’ pre-operative sitting and standing lumbar spine X-rays. Three-dimensional dynamic models were reconstructed using the Stryker Mako THA 4.0 software to assess bony and implant impingement both anteriorly and posteriorly, with default cup placement at 40° inclination and 20° anteversion. Femoral anteversion followed individual patient's native version. A 36mm hip ball was chosen for all cups equal or above 48mm and 32mm for those below. Anterior impingement was assessed by hip flexion and posterior impingement was assessed by hip extension.

113 patients were included. At neutral rotation and adduction, no patients had anterior implant impingement at hip flexion of 100°. 1.7% had impingement at 110°, 3.5% had impingement at 120°, 9.7% had impingement at 130°. With 20° of internal rotation and adduction, 0.8% had anterior implant impingement at hip flexion of 90°, 7.1% had impingement at 100° and 18.5% had impingement at 110°. With the hip externally rotated by 20°, 0.8% of patients had posterior implant impingement, and 8.8% bony impingement at 0° extension.

With enabling technology allowing accurate component positioning, hip precautions without limiting forward flexion in neutral position is safe given precise implant positioning and adequate osteophyte removal. Patients should only be cautioned about combined internal rotation, adduction with flexion.

Purposes of the study and background

Cognitive Functional Therapy (CFT) is a psychologically informed, physiotherapist-led intervention that targets the biopsychosocial complexity of persistent low back pain (LBP). CFT has demonstrated positive outcomes in two randomised controlled trials (RCT) but has not previously been evaluated in the United Kingdom National Health Service (NHS).

This study aimed to determine the feasibility of completing a definitive RCT, that will evaluate the clinical and cost-effectiveness of CFT in comparison to usual physiotherapy care (UPC) for people with persistent LBP in the NHS.

Purposes of the study and background

Cognitive Functional Therapy (CFT) is a complex intervention that targets the biopsychosocial nature of low back pain (LBP). The barriers and facilitators to CFT have not previously been researched in the United Kingdom National Health Service (NHS). This study aimed to explore the barriers and facilitators of CFT in the NHS ahead of a future clinical trial.

Aims

This study aimed to examine the effects of tumour necrosis factor-alpha (TNF-α) on osteoblasts in metal wear-induced bone loss.

Background

Mechanisms underlying implant failure remain incompletely described, though the presence of macrophage-mediated inflammatory reactions is well documented. Hypoxia has a critical role in many diseases and is known to be interdependent with inflammation. Metals used for joint replacements have also been reported to provoke hypoxia-like conditions. In view of this, we aim to investigate hypoxia-associated factors in aseptic loosening and osteoarthritis with a focus on macrophages.

Aims

Tissue responses to debris formed by abrasion of polymethylmethacrylate (PMMA) spacers at two-stage revision arthroplasty for prosthetic joint infection are not well described. We hypothesised that PMMA debris induces immunomodulation in periprosthetic tissues.

We investigated whether the presence of a pathological fracture increased the risk of local recurrence in patients with a giant cell tumour (GCT) of bone. We also assessed if curettage is still an appropriate form of treatment in the presence of a pathological fracture. We conducted a comprehensive review and meta-analysis of papers which reported outcomes in patients with a GCT with and without a pathological fracture at presentation. We computed the odds ratio (OR) of local recurrence in those with and without a pathological fracture.

We selected 19 eligible papers for final analysis. This included 3215 patients, of whom 580 (18.0%) had a pathological fracture. The pooled OR for local recurrence between patients with and without a pathological fracture was 1.05 (95% confidence interval (CI) 0.66 to 1.67, p = 0.854). Amongst the subgroup of patients who were treated with curettage, the pooled OR for local recurrence was 1.23 (95% CI 0.75 to 2.01, p = 0.417).

A post hoc sample size calculation showed adequate power for both comparisons.

There is no difference in local recurrence rates between patients who have a GCT of bone with and without a pathological fracture at the time of presentation. The presence of a pathological fracture should not preclude the decision to perform curettage as carefully selected patients who undergo curettage can have similar outcomes in terms of local recurrence to those without such a fracture.

Cite this article: Bone Joint J 2015;97-B:1566–71.

The peri-prosthetic tissue response to wear debris is complex and influenced by various factors including the size, area and number of particles. We hypothesised that the ‘biologically active area’ of all metal wear particles may predict the type of peri-prosthetic tissue response.

Peri-prosthetic tissue was sampled from 21 patients undergoing revision of a small diameter metal-on-metal (MoM) total hip arthroplasty (THA) for aseptic loosening. An enzymatic protocol was used for tissue digestion and scanning electron microscope was used to characterise particles. Equivalent circle diameters and particle areas were calculated. Histomorphometric analyses were performed on all tissue specimens. Aspirates of synovial fluid were collected for analysis of the cytokine profile analysis, and compared with a control group of patients undergoing primary THA (n = 11) and revision of a failed ceramic-on-polyethylene arthroplasty (n = 6).

The overall distribution of the size and area of the particles in both lymphocyte and non-lymphocyte-dominated responses were similar; however, the subgroup with lymphocyte-dominated peri-prosthetic tissue responses had a significantly larger total number of particles.

14 cytokines (interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, interferon (IFN)-γ, and IFN-gamma-inducible protein 10), chemokines (macrophage inflammatory protein (MIP)-1α and MIP-1ß), and growth factors (granulocyte macrophage colony stimulating factor (GM-CSF) and platelet derived growth factor) were detected at significantly higher levels in patients with metal wear debris compared with the control group.

Significantly higher levels for IL-1ß, IL-5, IL-10 and GM-CSF were found in the subgroup of tissues from failed MoM THAs with a lymphocyte-dominated peri-prosthetic response compared with those without this response.

These results suggest that the ‘biologically active area’ predicts the type of peri-prosthetic tissue response. The cytokines IL-1ß, IL-5, IL-10, and GM-CSF are associated with lymphocyte-dominated tissue responses from failed small-diameter MoM THA.

Cite this article: Bone Joint J 2015;97-B:917–23.

Summary Statement

CXCR4 gene and protein expression is regulated in a dose and time-dependent manner by metallic wear debris but not polyethylene wear debris in vitro and in vivo.

Purpose and Background

Traditional physiotherapy methods utilised in the management of NSCLBP have small effects on pain and disability and this is reflected by data previously collected by the host physiotherapy service. O'Sullivan has validated a novel classification system and matching treatment strategy known as Classification Based–Cognitive Functional Therapy (CB-CFT) for people with NSCLBP. Briefly, CB-CFT is a behavioural and functional management approach to NSCLBP. A recent RCT employing CB-CFT has demonstrated superior outcomes in comparison to traditional physiotherapy methods advocated by clinical practice guidelines. It was unknown if CB-CFT improved outcomes for people with NSCLBP attending an NHS physiotherapy service, therefore an evaluation of practice was proposed.

The optimal management of the tibial slope in achieving a high flexion angle in posterior-stabilised (PS) total knee replacement (TKR) is not well understood, and most studies evaluating the posterior tibial slope have been conducted on cruciate-retaining TKRs. We analysed pre- and post-operative tibial slope differences, pre- and post-operative coronal knee alignment and post-operative maximum flexion angle in 167 patients undergoing 209 TKRs. The mean pre-operative posterior tibial slope was 8.6° (1.3° to 17°) and post-operatively it was 8.0° (0.1° to 16.7°). Multiple linear regression analysis showed that the absolute difference between pre- and post-operative tibial slope (p < 0.001), post-operative coronal alignment (p = 0.02) and pre-operative range of movement (p < 0.001) predicted post-operative flexion. The variance of change in tibial slope became larger as the post-operative maximum flexion angle decreased. The odds ratio of having a post-operative flexion angle < 100° was 17.6 if the slope change was > 2°. Our data suggest that recreation of the anatomical tibial slope appears to improve maximum flexion after posterior-stabilised TKR, provided coronal alignment has been restored.

Cite this article: Bone Joint J 2013;95-B:1354–8.

Objective

A study was performed in a tertiary health care centre to evaluate outcomes of arthroplasty in Indian Population. Various factors which may affect knee flexion after surgery were also evaluated.

Background: Back pain in adult patients with a pars-interarticularis defect may be due to movement at the defect or abnormal inter-segmental movement at the adjacent degenerate disc. The suggested treatment of segmental fusion may not be necessary, if the defect alone was source of pain. We hypothesize that the defect may be the only source of pain in certain adults, even if the MRI scan shows an abnormal disc.

Objective: To form a protocol of management in adults with pars defect and adjacent level disc degeneration. To study the results of primary lysis repair using ‘AO Morscher clamp’ in patients with ‘spondylolysis’ or ‘Grade 1 ‘spondylolisthesis’.

Methods: This is a prospective study involving adults with ‘spondylolysis’ or ‘Grade 1 ‘spondylolisthesis’ not responding to conservative management and requiring interventional treatment. We investigated this subgroup of patients with lysis block and discography. On this basis, of a total of ten patients, seven were offered lysis repair and bone grafting using ‘Morscher’s clamp’; three were offered spinal fusion. Outcome was assessed using Visual Analogue Score (VAS) and Oswestry Disability Index (ODI) done pre-operatively and six months post-op.

Results: Out of ten patients (28 to 45 years; 4males and 6 females), seven patients underwent primary lysis repair using ‘AO Morscher clamp’. Union of pars achieved in all the patients by 4 months (Follow-up 4 months to 2 years). Three underwent fusion. Mean VAS improved from 7.2 to 1.2 in lysis repair group. Mean ODI improved from 68 % to 24%. All patients had full range of spinal movement postop.

Conclusion: A thorough pre-operative workup of patients with pars defect and adjacent level disc degeneration showed that pain is due to the pars defect in 70% of our cohort. This subgroup of patients could successfully be treated with ‘lysis repair’ rather than a more morbid procedure of ‘spinal fusion’.

Giant cell tumor (GCT) of bone is an osteolytic tumor that is locally aggressive and potentially metastatic. The pathogenesis of GCT is poorly understood. The purpose of this study was to harvest and culture primary cell lines from clinical specimens of GCT of bone and identify specific bone degradation proteases (matrix metalloproteinases: MMP-2, MMP-9) produced by the neoplastic stromal cells in vitro.

With approval by the McMaster University Biohazards and Ethics Review Boards, we acquired consent from five patients with GCT of bone, and harvested specimens intraoperatively. The specimens were chopped in DMEM containing 10% Fetal Bovine Serum, 2 mM L-glutamine, 100 U/ml penicillin and 100 mg/ml streptomycin. The cell suspensions were incubated at thirty-seven degrees (5% CO2 and 95% air) and cultivated. The cells were grown to confluence and taken through several passages until only proliferative cells were present. Immunocytochemistry with TRAP (Tartrate Resistant Acid Phosphatase) was used to confirm the stem cell origin of the propagative cells. Protein electrophoresis with embedded gelatin was used for detecting protease activity (MMP-2, MMP-9) on cell lysates and medium. P-aminophenyl mercuric acetate (APMA) was used to activate and ethylenediaminetetraacetic acid (EDTA) was used to block MMP-2 and MMP-9 activity. Our controls included serum free media, Human Osteosarcoma and Fibroblast cell lines.

Immunocytochemistry with TRAP confirmed that our propagative cells were not hematopoietic in origin but rather mesenchymal. Protein electrophoresis on cell lysates and medium identified the protease activity of MMP-2 and MMP-9 with lytic bands at appropriate molecular weights. APMA activated MMP-2 more than MMP-9, as indicated by increased relative density of bands. EDTA blocked the activity of both MMPs.

Our study confirmed the ability to cultivate the neoplastic stromal cells of GCT of bone from clinical specimens. Protein electrophoresis showed that activated MMP-2 and MMP-9 are secreted from the neoplastic stromal cells in vitro, suggesting a role for the tumor cells in bone destruction. These results are intriguing, as novel therapies in specific MMP inhibitors are currently underway for numerous disease processes.

In this study, we reviewed the records of 881 patients with fracture neck of femur over 5 years. Of these, 372 patients underwent hemiarthroplasty (231 cemented and 141 uncemented). The aim was to analyse the factors, which may contribute towards the mortality in cemented versus uncemented group.

The mean age in the cemented and uncemented group was 82 and 81 years respectively. 136 (58.8%) patients were operated within 24 hours of admission in the cemented group as compared to 63 (44.6%). The mean operative time was 81minutes for cemented hemiarthroplasty and 61 minutes for uncemented hemiarthroplasty. 77% of the cemented hemiarthroplasty was performed by Registrar grade as compared to 69% in the uncemented group. Of the 231 patients in the cemented group, 52% received general and 48% received spinal anaesthesia. Of the 141 patients in the uncemented group, 30% received general and 70% received spinal anaesthesia.

There was an 8% 30-day mortality compared to 11% 30-day mortality in uncemented group (p< 0.05). The mean age of patients in the mortality group was age 86 yrs in cement and 84 yrs in uncemented group. Most operations were done within 24–48 hours. There was significant co morbidity in patients who died. The average operative time of patients who died in both groups was same.

There was an increased mortality rate in the uncemented group as compared to the cemented group (p< 0.05). Based on our study, we conclude that cement is not a risk factor. Duration and timing of surgery is not associated with increased mortality. There was no difference in 30-day mortality rates between patients receiving general or spinal anaesthesia. Significant co morbid factor is associated with increased mortality.

Introduction A review of hip replacements performed in our hospital between 1991 and 2000 has identified a group of post-operative patients in whom recurrent dislocation has been deemed untreatable because of medical comorbidity. We tried to identify a group of patients at risk of recurrent dislocations. This paper presents our experience with the Kasselt cup in these patients

Methods We have used the Kasselt cup with indications being: a) prophylaxis, in patients with perceived greater risk of recurrent dislocation and b) treatment of recurrent (three or more) dislocations following THR. Patients were identified from clinical records and a National Joint Register. From 1998 to 2002, 51 patients underwent THR utilizing semi-constrained Kasselt cup. All living patients were invited for clinical and radiographic examination. Forty-eight patients (51 hips) were available for study. Thirty-nine patients were able to attend clinic and nine were interviewed by telephone. Average follow-up was 18.6 months (range 6 to 36 months). Average age was 75.6 years (range 56 to 92 years). Twenty-nine operations were done prophylactically and 22 for recurrent dislocations.

Results Three patients suffered further dislocations, from the recurrent dislocation group. One suffered a single dislocation post-operatively which was reduced by close manipulation and to-date has not re-dislocated. The second continued to dislocate. The third was revised with a Kasselt cup for recurrent dislocation and suffered three further dislocations. This patient was re-revised and to-date (six months) has had no further dislocation. The mean Harris Hip Score in the whole group was 79 (range 49 to 100). We have seen no dislocation in patients in the ‘at risk’ group in this short term

Conclusion The value of this prosthesis remains uncertain.

A review of total hip replacements (THR) performed in Palmerston North between 1991–2000 has identified a group of postoperative patients in whom recurrent dislocation has been previously deemed untreatable because of medical co-morbidity. From 1998 to 2001, 47 patients underwent THR utilizing a semi-constrained “Kasselt” cup to reduce the risk of dislocation. Indications for use of this cup were: Recurrent dislocation following primary or revision THR (3 or more dislocations) or perceived greater risk of recurrent dislocation eg. elderly, mental confusion, neurological compromise or fracture neck of femur.

This paper presents the early results in these 47 patients (49 hips). Clinical records and radiographs of all hip replacement patients were retrospectively reviewed to identify the “Kasselt” group and telephone contact was made for permission to participate in the study. All living patients were sent a self-evaluation questionnaire and invitation to attend clinic for physical examination and radiographs of the hip joint. Twenty-one patients were recurrent dislocators and 24 were at risk patients. Out of 45 living patients 36 were physically examined between 6 and 36 months following surgery. All collected data was statistically analysed using StatWave software.

Results: Forty-three of the 45 living patients (47 hips) had no dislocations following surgery. Two patients suffered further dislocation, both of whom were previously recurrent dislocators. One suffered a single dislocation postoperatively which was reduced closed and to date has not re-dislocated. The second continues to dislocate. The mean postoperative Harris Hip Score in the whole group is 79 (range 49–100). Early results reveal no dislocations in the “at risk” primary group.