Barbed sutures reduce arthrotomy closure duration compared to interrupted conventional sutures for total knee arthroplasty: a randomized controlled trial

BACKGROUND

The broad aim of this study was to compare the safety and efficacy of using barbed sutures versus standard-of-care sutures for closure of arthrotomy during total knee arthroplasty. Specifically, we compared the duration of arthrotomy closure, the number of sutures utilized for arthrotomy closure, and 90-day outcomes, including wound-related readmission, reoperation, and complications.

MATERIALS AND METHODS

A total of 60 patients undergoing primary total knee arthroplasty were enrolled in a prospective, blinded trial and randomized to receive either running closure of the arthrotomy with barbed sutures (n = 30) or interrupted closure with standard-of-care sutures (n = 30).

RESULTS

Arthrotomy closure time was significantly shorter in the barbed suture group (3 min ± 2 min) versus the standard-of-care group (13 min ± 5 min, p < 0.001). The average suture utilization for arthrotomy closure was 1 suture (range 1-2) versus 3 sutures (range 2-4) in the standard-of-care group (p < 0.001). The overall number of wound-related complications in the barbed suture group was 3/30 (10%) versus 3/30 (10%) in the standard-of-care group (p = 1.00). There was one dehiscence 1/30 (3%) in the standard-of-care group versus zero in the barbed suture group (p = 1.00). The rate of superficial surgical site infection was 1/30 (3%) in barbed suture versus zero in the standard-of-care groups (p = 1.00).

CONCLUSION

These results suggest barbed suture utilization may be faster and more resource-efficient than the use of standard-of-care sutures for arthrotomy closure in primary total knee arthroplasty without increased complications. CLINICALTRIALS.

GOV IDENTIFIER

NCT03285529.

Are adverse outcome rates higher in multiple sclerosis patients after total hip arthroplasty?

Aims

This study compared multiple sclerosis (MS) patients who underwent primary total hip arthroplasty (THA) with a matched cohort. Specifically, we evaluated: 1) implant survivorship; 2) functional outcomes (modified Harris Hip Scores (mHHS), Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS JR), and modified Multiple Sclerosis Impact Scale (mMSIS) scores (with the MS cohort also evaluated based on the disease phenotype)); 3) physical therapy duration and return to function; 4) radiographic outcomes; and 5) complications.

Patients and Methods

We reviewed our institution's database to identify MS patients who underwent THA between January 2008 and June 2016. A total of 34 MS patients (41 hips) were matched in a 1:2 ratio to a cohort of THA patients who did not have MS, based on age, body mass index (BMI), and Charlson/Deyo score. Patient records were reviewed for complications, and their functional outcomes and radiographs were reviewed at their most recent follow-up.

Results

Compared with the matched cohort, MS patients had lower all-cause implant survivorship at eight years (91.5% (95% confidence interval (CI) 82.7 to 100) vs 98.7% (95% CI 96.2 to 100)) (p = 0.033), lower mHHS scores (66 vs 80, p < 0.001), and HOOS JR scores (79 vs 88, p = 0.009). Multiple sclerosis patients also required more physiotherapy (five weeks vs three weeks, p = 0.002) and took longer to return to baseline (seven weeks vs five weeks, p = 0.010) than the matched cohort. Furthermore, MS patients had more complications than the non-MS patients (six vs zero, p < 0.001). The worse outcomes of the MS group can potentially be explained by predisposition of these patients to mechanical complications and progression of their disease during the period of this study, as demonstrated by worsening of the mMSIS scores (2.9 vs 3.4; p = 0.008).

Conclusion

MS patients had lower implant survivorship, lower functional outcome scores, and increased complication rates; in addition, MS patients took longer to return to their baseline functional level after THA. Cite this article: Bone Joint J 2018;100-B:875-81.

An evidence-based guide to the treatment of osteonecrosis of the femoral head

Non-traumatic osteonecrosis of the femoral head is a potentially devastating condition, the prevalence of which is increasing. Many joint-preserving forms of treatment, both medical and surgical, have been developed in an attempt to slow or reverse its progression, as it usually affects young patients. However, it is important to evaluate the best evidence that is available for the many forms of treatment considering the variation in the demographics of the patients, the methodology and the outcomes in the studies that have been published, so that it can be used effectively. The purpose of this review, therefore, was to provide an up-to-date, evidence-based guide to the management, both non-operative and operative, of non-traumatic osteonecrosis of the femoral head. Cite this article: Bone Joint J 2017;99-B:1267-79.

International consensus on the definition and classification of fibrosis of the knee joint

AIMS

The aim of this consensus was to develop a definition of post-operative fibrosis of the knee.

PATIENTS AND METHODS

An international panel of experts took part in a formal consensus process composed of a discussion phase and three Delphi rounds.

RESULTS

Post-operative fibrosis of the knee was defined as a limited range of movement (ROM) in flexion and/or extension, that is not attributable to an osseous or prosthetic block to movement from malaligned, malpositioned or incorrectly sized components, metal hardware, ligament reconstruction, infection (septic arthritis), pain, chronic regional pain syndrome (CRPS) or other specific causes, but due to soft-tissue fibrosis that was not present pre-operatively. Limitation of movement was graded as mild, moderate or severe according to the range of flexion (90° to 100°, 70° to 89°, < 70°) or extension deficit (5° to 10°, 11° to 20°, > 20°). Recommended investigations to support the diagnosis and a strategy for its management were also agreed.

CONCLUSION

The development of standardised, accepted criteria for the diagnosis, classification and grading of the severity of post-operative fibrosis of the knee will facilitate the identification of patients for inclusion in clinical trials, the development of clinical guidelines, and eventually help to inform the management of this difficult condition. Cite this article: Bone Joint J 2016;98-B:1479-88.

The effects of various physical non-operative modalities on the pain in osteoarthritis of the knee

The purpose of this study was to evaluate the effect of various non-operative modalities of treatment (transcutaneous electrical nerve stimulation (TENS); neuromuscular electrical stimulation (NMES); insoles and bracing) on the pain of osteoarthritis (OA) of the knee. We conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify the therapeutic options which are commonly adopted for the management of osteoarthritis (OA) of the knee. The outcome measurement tools used in the different studies were the visual analogue scale and The Western Ontario and McMaster Universities Arthritis Index pain index: all pain scores were converted to a 100-point scale. A total of 30 studies met our inclusion criteria: 13 on insoles, seven on TENS, six on NMES, and four on bracing. The standardised mean difference (SMD) in pain after treatment with TENS was 1.796, which represented a significant reduction in pain. The significant overall effect estimate for NMES on pain was similar to that of TENS, with a SMD of 1.924. The overall effect estimate of insoles on pain was a SMD of 0.992. The overall effect of bracing showed a significant reduction in pain of 1.34. Overall, all four non-operative modalities of treatment were found to have a significant effect on the reduction of pain in OA of the knee. This study shows that non-operative physical modalities of treatment are of benefit when treating OA of the knee. However, much of the literature reviewed evaluates studies with follow-up of less than six months: future work should aim to evaluate patients with longer follow-up.

Systemic cobalt toxicity from total hip arthroplasties

As adverse events related to metal on metal hip arthroplasty have been better understood, there has been increased interest in toxicity related to the high circulating levels of cobalt ions. However, distinguishing true toxicity from benign elevations in cobalt levels can be challenging. The purpose of this review is to examine the use of cobalt alloys in total hip arthroplasty, to review the methods of measuring circulating cobalt levels, to define a level of cobalt which is considered pathological and to review the pathophysiology, risk factors and treatment of cobalt toxicity. To the best of our knowledge, there are 18 published cases where cobalt metal ion toxicity has been attributed to the use of cobalt-chromium alloys in hip arthroplasty. Of these cases, the great majority reported systemic toxic reactions at serum cobalt levels more than 100 μg/L. This review highlights some of the clinical features of cobalt toxicity, with the goal that early awareness may decrease the risk factors for the development of cobalt toxicity and/or reduce its severity.

Take home message: Severe adverse events can arise from the release of cobalt from metal-on-metal arthroplasties, and as such, orthopaedic surgeons should not only be aware of the presenting problems, but also have the knowledge to treat appropriately.

Cite this article: Bone Joint J 2016;98-B:14–20.

Systemic cobalt toxicity from total hip arthroplasties

Recently, the use of metal-on-metal articulations in total hip arthroplasty (THA) has led to an increase in adverse events owing to local soft-tissue reactions from metal ions and wear debris. While the majority of these implants perform well, it has been increasingly recognised that a small proportion of patients may develop complications secondary to systemic cobalt toxicity when these implants fail. However, distinguishing true toxicity from benign elevations in cobalt ion levels can be challenging.

The purpose of this two part series is to review the use of cobalt alloys in THA and to highlight the following related topics of interest: mechanisms of cobalt ion release and their measurement, definitions of pathological cobalt ion levels, and the pathophysiology, risk factors and treatment of cobalt toxicity. Historically, these metal-on-metal arthroplasties are composed of a chromium-cobalt articulation.

The release of cobalt is due to the mechanical and oxidative stresses placed on the prosthetic joint. It exerts its pathological effects through direct cellular toxicity.

This manuscript will highlight the pathophysiology of cobalt toxicity in patients with metal-on-metal hip arthroplasties.

Take home message: Patients with new or evolving hip symptoms with a prior history of THA warrant orthopaedic surgical evaluation. Increased awareness of the range of systemic symptoms associated with cobalt toxicity, coupled with prompt orthopaedic intervention, may forestall the development of further complications.

Cite this article: Bone Joint J 2016;98-B:6–13.

Preliminary results of a phase II randomized study to determine the efficacy and safety of genetically engineered allogeneic human chondrocytes expressing TGF-β1 in patients with grade 3 chronic degenerative joint disease of the knee

OBJECTIVE

The aim of this study was to preliminarily evaluate the efficacy and outcomes of injectable genetically engineered chondrocytes virally transduced with TGF-β1 (GEC-TGF-β1) compared to placebo.

DESIGN

A multi-center, double-blinded, placebo-controlled, randomized study of adults with knee osteoarthritis. A total of 102 patients were 2:1 randomized to GEC-TGF-β1 or placebo. Primary outcomes assessed were (1) function of the knee joint, scored using the International Knee Documentation Committee (IKDC); and (2) pain, measured by Visual Analog Scale (VAS). Secondary endpoints assessed were pain and analgesic use, quality of life (QOL), and adverse events (AEs) including need for total knee arthroplasty after treatment.

RESULTS

IKDC showed significant improvement in the GEC-TGF-β1 group over the placebo at week 12 (least mean square difference (LSMD): 10.3; P = 0.0342), week 52 (LSMD: 13.6; P = 0.0082), and overall (LSMD: 8.6; P = 0.0453). VAS Analysis showed a significant improvement in GEC-TGF-β1 group compared to placebo at weeks 12 (LSMD: -13.8; P = 0.0162), 52 (LSMD: -13.1; P = 0.0332), and overall (LSMD: -10.1; P = 0.0350). Reduction in pain severity at week 12 and 52, frequency at 24 h and week 52, and the percentage of patients in the GEC-TGF-β1 group receiving analgesics at week 4 (27 vs 40%) and 12 (27 vs 37%) was observed.

CONCLUSIONS

GEC-TGF-β1 patients had more positive responses on the IKDC, VAS, and were less likely to require analgesics.

TRIAL NUMBER

ClinicalTrials.gov (NCT01221441) - "Study of TG-C in Patients with Grade 3 Degenerative Joint Disease of the Knee".

A placebo-controlled randomised trial to assess the effect of TGF-ß1-expressing chondrocytes in patients with arthritis of the knee

The aim of this study was to assess the effect of injecting genetically engineered chondrocytes expressing transforming growth factor beta 1 (TGF-β1) into the knees of patients with osteoarthritis. We assessed the resultant function, pain and quality of life.

A total of 54 patients (20 men, 34 women) who had a mean age of 58 years (50 to 66) were blinded and randomised (1:1) to receive a single injection of the active treatment or a placebo. We assessed post-treatment function, pain severity, physical function, quality of life and the incidence of treatment-associated adverse events. Patients were followed at four, 12 and 24 weeks after injection.

At final follow-up the treatment group had a significantly greater improvement in the mean International Knee Documentation Committee score than the placebo group (16 points; -18 to 49, vs 8 points; -4 to 37, respectively; p = 0.03). The treatment group also had a significantly improved mean visual analogue score at final follow-up (-25; -85 to 34, vs -11 points; -51 to 25, respectively; p = 0.032). Both cohorts showed an improvement in Western Ontario and McMaster Osteoarthritis Index and Knee Injury and Osteoarthritis Outcome Scores, but these differences were not statistically significant. One patient had an anaphylactic reaction to the preservation medium, but recovered within 24 hours. All other adverse events were localised and resolved without further action.

This technique may result in improved clinical outcomes, with the aim of slowing the degenerative process, leading to improvements in pain and function. However, imaging and direct observational studies are needed to verify cartilage regeneration. Nevertheless, this study provided a sufficient basis to proceed to further clinical testing.

Cite this article: Bone Joint J 2015;97-B:924–32.

Osteonecrosis of the femoral head

Symptomatic hip osteonecrosis is a disabling condition with a poorly understood aetiology and pathogenesis. Numerous treatment options for hip osteonecrosis are described, which include non-operative management and joint preserving procedures, as well as total hip replacement (THR). Non-operative or joint preserving treatment may improve outcomes when an early diagnosis is made before the lesion has become too large or there is radiographic evidence of femoral head collapse. The presence of a crescent sign, femoral head flattening, and acetabular involvement indicate a more advanced-stage disease in which joint preserving options are less effective than THR. Since many patients present after disease progression, primary THR is often the only reliable treatment option available. Prior to the 1990s, outcomes of THR for osteonecrosis were poor. However, according to recent reports and systemic reviews, it is encouraging that with the introduction of newer ceramic and/or highly cross-linked polyethylene bearings as well as highly-porous fixation interfaces, THR appears to be a reliable option in the management of end-stage arthritis following hip osteonecrosis in this historically difficult to treat patient population.

Cite this article: Bone Joint J 2013;95-B, Supple A:46–50.

Surgical challenges and clinical outcomes of total hip replacement in patients with Down’s syndrome

Down’s syndrome is associated with a number of musculoskeletal abnormalities, some of which predispose patients to early symptomatic arthritis of the hip. The purpose of the present study was to review the general and hip-specific factors potentially compromising total hip replacement (THR) in patients with Down’s syndrome, as well as to summarise both the surgical techniques that may anticipate the potential adverse impact of these factors and the clinical results reported to date. A search of the literature was performed, and the findings further informed by the authors’ clinical experience, as well as that of the hip replacement in Down Syndrome study group. The general factors identified include a high incidence of ligamentous laxity, as well as associated muscle hypotonia and gait abnormalities. Hip-specific factors include: a high incidence of hip dysplasia, as well as a number of other acetabular, femoral and combined femoroacetabular anatomical variations. Four studies encompassing 42 hips, which reported the clinical outcomes of THR in patients with Down’s syndrome, were identified. All patients were successfully treated with standard acetabular and femoral components. The use of supplementary acetabular screw fixation to enhance component stability was frequently reported. The use of constrained liners to treat intra-operative instability occurred in eight hips. Survival rates of between 81% and 100% at a mean follow-up of 105 months (6 to 292) are encouraging. Overall, while THR in patients with Down’s syndrome does present some unique challenges, the overall clinical results are good, providing these patients with reliable pain relief and good function.

Cite this article: Bone Joint J 2013;95-B, Supple A:41–5.

The Hip Society: algorithmic approach to diagnosis and management of metal-on-metal arthroplasty

Since 1996 more than one million metal-on-metal articulations have been implanted worldwide. Adverse reactions to metal debris are escalating. Here we present an algorithmic approach to patient management. The general approach to all arthroplasty patients returning for follow-up begins with a detailed history, querying for pain, discomfort or compromise of function. Symptomatic patients should be evaluated for intra-articular and extra-articular causes of pain. In large head MoM arthroplasty, aseptic loosening may be the source of pain and is frequently difficult to diagnose. Sepsis should be ruled out as a source of pain. Plain radiographs are evaluated to rule out loosening and osteolysis, and assess component position. Laboratory evaluation commences with erythrocyte sedimentation rate and C-reactive protein, which may be elevated. Serum metal ions should be assessed by an approved facility. Aspiration, with manual cell count and culture/sensitivity should be performed, with cloudy to creamy fluid with predominance of monocytes often indicative of failure. Imaging should include ultrasound or metal artifact reduction sequence MRI, specifically evaluating for fluid collections and/or masses about the hip. If adverse reaction to metal debris is suspected then revision to metal or ceramic-on-polyethylene is indicated and can be successful. Delay may be associated with extensive soft-tissue damage and hence poor clinical outcome.

The Hip Society: algorithmic approach to diagnosis and management of metal-on-metal arthroplasty

Since 1996 more than one million metal-on-metal articulations have been implanted worldwide. Adverse reactions to metal debris are escalating. Here we present an algorithmic approach to patient management. The general approach to all arthroplasty patients returning for follow-up begins with a detailed history, querying for pain, discomfort or compromise of function. Symptomatic patients should be evaluated for intra-articular and extra-articular causes of pain. In large head MoM arthroplasty, aseptic loosening may be the source of pain and is frequently difficult to diagnose. Sepsis should be ruled out as a source of pain. Plain radiographs are evaluated to rule out loosening and osteolysis, and assess component position. Laboratory evaluation commences with erythrocyte sedimentation rate and C-reactive protein, which may be elevated. Serum metal ions should be assessed by an approved facility. Aspiration, with manual cell count and culture/sensitivity should be performed, with cloudy to creamy fluid with predominance of monocytes often indicative of failure. Imaging should include ultrasound or metal artifact reduction sequence MRI, specifically evaluating for fluid collections and/or masses about the hip. If adverse reaction to metal debris is suspected then revision to metal or ceramic-on-polyethylene is indicated and can be successful. Delay may be associated with extensive soft-tissue damage and hence poor clinical outcome.

The use of a Type-I lyophilisate collagen as an osteoinductive factor in pseudarthroses of the forearm

The purpose of this study was to assess the use of a novel bone void filler consisting of Type I collagen and various growth factors (VEGF, TGFβ-1, TGFβ-2, IGF-1, BMP-2, BMP-3, and BMP-7) and surgical fixation to treat diaphyseal forearm pseudarthroses. Eleven patients underwent an osteosynthesis procedure for isolated pseudarthrosis fractures of the forearm (six radial and five ulnar diaphysis). The mean duration between the initial failed surgical fixation and re-operation was 38 weeks. Radiographic signs of fracture healing after the application of the bone void filler were noted at a mean of 5 weeks, and complete fracture consolidation was achieved at a mean of 6 weeks. All patients demonstrated improved range of motion and grip strength. Additionally, all patients were pain-free by 6 weeks. The combination of a novel bovine bone-derived bone void filler and stable internal fixation led to union and rapid healing of forearm pseudarthroses.

Management of arthritis of the hip in the young adult

Arthritis of the hip in the young adult can be a disabling condition. Recent years have witnessed extensive research related to the management of this condition. This article reviews the current status with regard to aetiology, diagnosis and treatment of arthritis of the hip in the young adult.

Percutaneous drilling for the treatment of secondary osteonecrosis of the knee

Osteonecrosis of the knee comprises two separate disorders, primary spontaneous osteonecrosis which is often a self-limiting condition and secondary osteonecrosis which is associated with risk factors and a poor prognosis. In a series of 61 knees (38 patients) we analysed secondary osteonecrosis of the knee treated by a new technique using multiple small percutaneous 3 mm drillings. Total knee replacement was avoided in 59 knees (97%) at a mean follow-up of 3 years (2 to 4). Of the 61 knees, 56 (92%) had a successful clinical outcome, defined as a Knee Society score greater than 80 points. The procedure was successful in all 24 knees with small lesions compared with 32 of 37 knees (86%) with large lesions. All the procedures were performed as day cases and there were no complications. This technique appears to have a low morbidity, relieves symptoms and delays more invasive surgery.

Reinfusion drains after primary total hip and total knee arthroplasty

The purposes of this study were to evaluate the efficacy of intraoperative surgeon-elected reinfusion drain placement and to determine whether drainage at 90 minutes is useful in predicting the need for a reinfusion drain. In the standard drain hip arthroplasty group, 6 of 30 patients (20%) received a reinfusion, similar to the 11 of 41 patients (27%) in the reinfusion drain group. In the total knee arthroplasty group, 38 of 45 patients (84%) in the standard group had reinfusion, similar to the 23 of 27 patients (85%) in the reinfusion drain group. The surgeon could not predict intraoperatively which patients would need a subsequent reinfusion drain. However, in more than 94% of the cases, one could know by 90 minutes postoperatively whether a reinfusion would be necessary. We believe that a drain that can be converted to a reinfusion drain in the recovery room would be the most cost-effective drain system.

Anatomy of the knee extensor mechanism: correlation with patellofemoral arthrosis

The patellofemoral articulation is a common and significant source of disability and discomfort in the aging population. This study examined the anatomy of the knee extensor mechanism in patients having primary total knee arthroplasties, characterized the anatomic variations of the extensor mechanism, and correlated these findings with the location and extent of osteoarthritic change of the patellar undersurface. Sixty-two knees (57 patients) were evaluated prospectively. Specific characteristics that were analyzed included the mean Outerbridge grade for rating patellar cartilage degeneration and anatomic patterns of the extensor mechanism. Knees with a quadriceps tendon width at 2 and 5 cm above the patella that differed by less than 1 cm had more statistically significant patellar degeneration in all patellar locations than knees with tendon width differences greater than 1 cm. Anatomic variations, such as tendons with minimal increments in width in the proximal-distal direction, may be associated with an increasing amount of patellar arthrosis at the lateral facet, central ridge, and, most significantly, medial facet.

Outcomes of limited femoral resurfacing arthroplasty compared with total hip arthroplasty for osteonecrosis of the femoral head

This study compared the results of limited femoral head resurfacing arthroplasty versus total hip arthroplasty (THA) for osteonecrosis. Thirty consecutive patients who had undergone a femoral head resurfacing procedure for osteonecrosis of the femoral head were compared with 30 consecutive patients who had undergone a THA. Both groups of patients had Steinberg stage III or IV disease with no acetabular cartilage involvement radiographically and by intraoperative inspection. At a 7-year mean follow-up for the resurfacing group and an 8-year mean follow-up for the THA group, the survival rate was 90% and 93% (P=.3). This study supports the femoral head resurfacing procedure as an alternative to THA for the time period studied.

Use of fibrin sealant to reduce bloody drainage and hemoglobin loss after total knee arthroplasty: a brief note on a randomized prospective trial

BACKGROUND

A phase-III trial that included fifty-three patients undergoing unilateral primary total knee arthroplasty with cement was conducted to investigate the hemostatic efficacy of fibrin sealant.

METHODS

Following cementing of the joint, 10 mL of fibrin sealant was sprayed onto the wound before tourniquet deflation and wound closure. No placebo was used in the control group. All patients received drains.

RESULTS

Within twelve hours after the surgery, the amount of bloody drainage was 184.5 +/- 28.9 mL (mean and standard error) in the fibrin-sealant group (information available for twenty-three patients) and 408.3 +/- 54.6 mL in the control group (information available for twenty-three patients) (p = 0.002, after adjustment for variance in the time that the drainage was measured). On the first postoperative day, the hemoglobin level had decreased by 20.1 +/- 2.1 g/L in the fibrin-sealant group (information available for twenty-two patients) and by 27.3 +/- 2.1 g/L in the control group (information available for twenty-four patients). After adjustment for baseline values, the decrease in the hemoglobin level was 28.9% less in the fibrin-sealant group than in the control group (p = 0.005, 95% confidence limits = 10.2, 43.7). There were no seroconversions in the fibrin-sealant group.

CONCLUSION

These results suggest that fibrin sealant can safely reduce bloody drainage following total knee arthroplasty while maintaining higher hemoglobin levels.

Strut-autografting with and without osteogenic protein-1 : a preliminary study of a canine femoral head defect model

BACKGROUND

Osteonecrosis of the femoral head frequently leads to collapse of the articular cartilage and to disabling osteoarthritis, which ultimately may necessitate joint arthroplasty. One treatment method that has had moderate success is the so-called trapdoor approach, which involves excavation of diseased (necrotic) bone followed by bone-grafting. Augmentation of this procedure with various growth and differentiation factors may improve the outcome. We developed a canine model that mimics the clinical situation with trapdoor bone-grafting. The objective of this study was to evaluate the effect of the addition of osteogenic protein-1 on healing following the trapdoor procedure with strut-autografting.

METHODS

Thirty-four skeletally mature dogs were used in the experiment. After capsulotomy, a trapdoor was created in the anterolateral surface of the femoral head and a 2-cm-diameter subchondral area of bone was removed. In the phase-I experiments, seven dogs had no treatment of the defect (Group I) and nine dogs were treated with strut-grafting (Group II). In phase II, the procedure was modified by collapsing the trapdoor into the created defect intraoperatively in eighteen dogs, which were divided into three equal groups: six untreated defects were left collapsed (Group III), six were treated with bone graft (Group IV), and six were treated with bone graft augmented with osteogenic protein-1 (Group V).

RESULTS

Three of the seven femoral heads in Group I (untreated defect) and one of the nine heads in Group II (grafting without collapsing of the trapdoor) had evidence of cartilage collapse. Inspection of sagittal slices and radiographs revealed an unfilled residual defect in all Group-I heads, whereas all Group-II heads were well healed. The mean normalized stiffness value was significantly larger in Group II than it was in Group I. On visual inspection, depression was noted in all of the femoral heads in Group III (untreated defect; trapdoor left collapsed). In both Group IV and Group V (grafting without and with osteogenic protein-1), the trapdoor cartilage appeared to be essentially normal. Groups IV and V had more radiographic healing than did Group III. The defects in Group V (grafting with osteogenic protein-1) healed faster radiographically than did those in Group IV (grafting without osteogenic protein-1).

CONCLUSIONS

Moderate-to-excellent healing was seen both radiographically and biomechanically by four months in the groups treated with grafting, with and without osteogenic protein-1, whereas untreated defects did not heal.

CLINICAL RELEVANCE

Symptomatic osteonecrosis of the femoral head is a clinical challenge. The animal model in the current study is a useful tool for the evaluation of methods to treat osteonecrosis of the femoral head. Studies investigating additional time-periods between implantation of osteogenic protein-1 and assessment of results as well as different doses of osteogenic protein-1 are warranted.

Atraumatic osteonecrosis of the patella

Atraumatic secondary osteonecrosis of the patella is a rare entity and has been reported in only several case reports. The purpose of this study was to define the clinical and radiographic characteristics and outcome of this disease. Osteonecrosis of the patella was found in 25 knees in 19 patients. The mean age was 42 years (range, 21-63 years). Eighteen (95%) patients had greater than 2 g of lifetime corticosteroid exposure, and six (32%) patients had systemic lupus erythematosus. Osteonecrosis was found in the superior pole of the patella in all 23 knees (17 patients) that had magnetic resonance imaging. Osteonecrosis was apparent on plain radiographs in five knees (20%) in four patients, and only one knee (4%) in one patient had collapse of the posterior articulating surface of the patella. One (4%) patient presented with anterior knee pain localized to the patella. At a mean followup of 4 years (range, 2-18 years), none of the patients had an intervention that focused on treating the patellar lesion. Patellar osteonecrosis is characterized by patients with coincident lesions of the distal femur and the proximal tibia and lesions localized to the superior pole of the patella. It is a nonprogressive disease that does not warrant surgical exploration.

Steroid-associated osteonecrosis of the knee: a comprehensive review

Steroid-associated osteonecrosis of the knee is a disease of young patients (generally younger than 45 years old) who often have underlying immunocompromising disorders. Although many theories have been postulated, the exact pathophysiology of the disorder is still unknown. Precollapse lesions can be treated with core decompression for prolonged symptomatic relief. Later-stage lesions are treated with total knee replacements, which have less than optimal results reported to date.

Human immunodeficiency virus testing for elective orthopedic procedures: results in a community-based hospital

Between January 1, 1989 and July 31, 1995, voluntary preoperative screening tests for human immunodeficiency virus (HIV) infection, using an enzyme-linked immunosorbant assay, were completed on 2,727 patients who underwent elective orthopedic surgical procedures. There were 2,719 (99.7%) negative, 4 (0.15%) positive, and 3 (0.11%) false-positive results; 1 test was indeterminate (0.04%). All 4 positive patients were men with a mean age of 32 years (range: 26-43 years). Although the prevalence of positive tests is low in this setting, voluntary testing alerts the surgeon to higher risk patients, does not sacrifice patient care, and enables the incorporation of more extensive precautionary measures in the operating room to minimize occupational risks to the surgical team.

Evaluation of preoperative cultures before second-stage reimplantation of a total knee prosthesis complicated by infection. A comparison-group study

BACKGROUND

Two-stage reimplantation has proven to be highly successful in the treatment of patients with infection at the site of a total knee arthroplasty. However, up to 20 percent of patients have a recurrence of infection following this treatment. The purpose of our study was to determine whether aspiration of the affected joint and culture of the specimen, performed before reimplantation and after discontinuation of antibiotic therapy, would help to identify patients who might have a recurrent infection.

METHODS

We prospectively followed sixty-nine patients who were treated for a culture-proven deep infection at the site of a total knee arthroplasty. Group I consisted of thirty-five patients who were treated with removal of the prosthetic components and irrigation and debridement of the joint, followed by six weeks of antibiotic therapy and reimplantation of a prosthesis. Group II was composed of thirty-four patients who were treated with removal of the components and irrigation and debridement of the joint, six weeks of antibiotic therapy, and then repeat culture four weeks after the antibiotic course had ended. If the culture was negative, the patient was managed with a second-stage reimplantation of a prosthesis. If the culture was positive, the protocol was repeated, beginning with irrigation and debridement. The two groups were similar with regard to male-to-female ratio, age, preoperative Knee Society scores, time since primary surgery, types of infectious organisms, duration of symptoms, duration of follow-up, and number of previous revisions. All of the patients were evaluated clinically with use of the objective scoring system of the Knee Society and were followed with serial radiographs. Success was defined as no infection and a functional prosthesis, with a Knee Society score of at least 75 points at the last (thirty-six-month-minimum) follow-up evaluation.

RESULTS

Of the thirty-five patients in Group I, five (14 percent) had recurrence of infection. One of the patients was managed with a successful second-stage revision, three were managed with arthrodesis of the knee, and one continued with chronic antibiotic suppressive treatment. Of the thirty-four patients in Group II, three (9 percent) had a positive culture after the course of antibiotics. The protocol was repeated for all three, and they subsequently had a successful second revision. One other patient (3 percent) in Group II, who had a negative culture, had a recurrent infection and was eventually managed with arthrodesis of the knee.

CONCLUSIONS

Prerevision cultures, grown after discontinuation of antibiotic treatment and before reimplantation of the components, helped to identify the patients with infection at the site of a total knee arthroplasty in whom the infection might recur. The performance of aspiration and cultures resulted in a substantial improvement in the clinical outcome.

Femoral head osteonecrosis: detection and grading by using a rapid MR imaging protocol

PURPOSE

To design and evaluate a limited magnetic resonance (MR) imaging examination that can be performed rapidly and potentially inexpensively in patients with clinical suspicion of osteonecrosis.

MATERIALS AND METHODS

Both a limited and a full hip MR examination were performed prospectively in 179 hips in 92 patients with clinical suspicion of femoral head osteonecrosis. The presence of osteonecrosis was determined by two radiologists. The percentage of involvement of the femoral head weight-bearing surface was evaluated subsequently for osteonecrosis-positive hips on both sets of images.

RESULTS

Both examinations were performed successfully in all cases. Agreement between the limited and full examinations for presence of osteonecrosis was 98.9% (177 of 179 cases; kappa, 0.97). Forty-six (92%) of 50 patients with femoral head osteonecrosis at both examinations were placed in the appropriate quartile of percentage of femoral head weight-bearing surface involvement by both readers (weighted kappa, 0.94). Incidental findings were made at the full examination that could not be made or were difficult to make at the limited examination.

CONCLUSION

There was excellent agreement between the full and screening MR examinations for both detection of and determining the extent of osteonecrosis. The time and potential cost reduction achieved with a limited examination may allow introduction of MR imaging earlier in the diagnosis of femoral head osteonecrosis, as well as its more widespread use in patient care.

Total hip arthroplasty in patients receiving Workers' Compensation

Numerous studies have reported on the adverse outcome of patients who sustain job-related injuries. In addition, studies have reported poor outcomes in patients receiving Workers' Compensation who undergo elective surgery. This study sought to determine the influence of Workers' Compensation on the outcome of patients who had undergone primary total hip arthroplasty. Between January 1984 and December 1996, 44 patients (48 hips) were studied. Of these, 17 were men and five were women with a mean age of 45 years (range, 27-76 years) at the time of surgery. These patients were receiving compensation benefits and were matched directly with a group of 22 patients who had 24 arthroplasties and were not receiving compensation. After a mean final followup of 77 months (range, 25-125 months), the compensation group had a mean Harris hip score of 86 points (range, 54-95 points). The matched control group had a mean Harris hip score of 92 points (range, 79-100 points) at a mean final duration of followup of 80 months. Two patients (9%) had undergone revision surgery for aseptic loosening at 28 and 67 months. The percentage of patients with good or excellent results did not differ significantly between the two groups. Based on these findings, the authors think that Workers' Compensation does not negatively influence the outcome of total hip arthroplasty.

Atraumatic osteonecrosis of the knee

BACKGROUND

The purposes of this study were to define the clinical, demographic, and radiographic patterns of atraumatic osteonecrosis of the distal part of the femur and the proximal part of the tibia at presentation and to report the outcome of treatment of this condition.

METHODS

Two hundred and forty-eight knees in 136 patients who were younger than the age of fifty-five years were treated at our institution between July 1, 1974, and September 15, 1998, for atraumatic osteonecrosis of the distal part of the femur or the proximal part of the tibia, or both. Demographic and radiographic features were characterized. The results of nonoperative treatment, core decompression, arthroscopic debridement, and total knee arthroplasty were evaluated.

RESULTS

There were 106 female patients and thirty male patients, and their mean age was thirty-six years (range, fifteen to fifty-four years) at the time of diagnosis. One hundred and one patients (74 percent) had involvement of other large joints, with eighteen (13 percent) presenting initially with knee symptoms. One hundred and one patients (74 percent) had a disease that affected the immune system; sixty-seven of them had systemic lupus erythematosus. One hundred and twenty-three patients (90 percent) had a history of corticosteroid use. Technetium-99m bone-scanning missed lesions in sixteen (29 percent) of fifty-six knees. Eight (20 percent) of forty-one initially symptomatic knees treated nonoperatively had a successful clinical outcome (a Knee Society score of at least 80 points and no additional surgery) at a mean of eight years. The knees that remained severely symptomatic for three months were treated with either core decompression (ninety-one knees) or total knee arthroplasty (seven knees). Seventy-two (79 percent) of the ninety-one knees treated with core decompression had a good or excellent clinical outcome at a mean of seven years. Efforts to avoid total knee arthroplasty with repeat core decompression or arthroscopic debridement led to a successful outcome in fifteen (60 percent) of twenty-five knees. Thirty-four (71 percent) of forty-eight knees treated with total knee arthroplasty had a successful clinical outcome at a mean of nine years.

CONCLUSIONS

Atraumatic osteonecrosis of the knee predominantly affects women, and in our study it was associated with corticosteroid use in 90 percent of the patients. Evaluation should include standard radiographic and magnetic resonance imaging of all symptomatic joints. Prognosis was negatively related to large juxta-articular lesions. Nonoperative treatment should be reserved for asymptomatic knees only. Core decompression was successful (a Knee Society score of at least 80 points and no additional surgery) in 79 percent of the knees in which the disease was in an early stage. Total knee arthroplasty was successful in only 71 percent of the knees.

Atraumatic osteonecrosis of the humeral head

OBJECTIVE

To define the epidemiology, clinical and radiographic presentation, treatment, and prognosis of atraumatic osteonecrosis of the humeral head.

METHODS

Of the 1,056 patients managed for osteonecrosis of any joint between July 1, 1974, and December 1, 1996, 127 shoulders in 73 patients were treated for atraumatic osteonecrosis of the proximal humerus. Clinical and radiographic characterization of this patient cohort was performed.

RESULTS

At presentation, there were 47 women and 26 men with a mean age of 41 years (range 20-60). Numerous associated factors were noted: alcohol use (38%), moderate smoking (30%), asthma (8%), and nephrosis (3%). A corticosteroid association was noted in 60 patients (82%) and 42 of the patients (58%) had an immunocompromising disease. The severity of humeral head osteonecrosis did not correlate with dose or duration of corticosteroid therapy. According to the modified Ficat and Arlet radiographic staging system, there were 20 shoulders with Stage I disease, 55 shoulders with stage II disease, and 52 shoulders with Stage ITI or IV disease. Seventy-four of the shoulders treated with core decompression (78%) had good to excellent clinical outcomes at a mean followup of 6 years (range 2-21). Fourteen of the 16 patients (88%) treated with hemiarthroplasty or total shoulder arthroplasty were clinically successful at a mean followup 4 years (range 2-11).

CONCLUSION

We observed a low incidence of humeral head involvement in the osteonecrosis patient cohort (7% of all osteonecrosis patients), and a high incidence of corticosteroid use (82%). hip involvement (81%), and bilateral disease (74%). Osteonecrosis of the humeral head should be suspected in patients presenting with shoulder pain and a history of osteonecrosis in other joints. Hip screening for osteonecrosis is advocated in patients with shoulder involvement. Early detection of shoulder osteonecrosis may permit a more conservative, joint-sparing approach as an alternative to surgical management.

Infected total knee arthroplasty treated by arthroscopic irrigation and débridement

Sixteen patients with infected total knee arthroplasties (4 postoperative and 12 late hematogenous) were treated by arthroscopic irrigation and débridement. All patients had < or = 7 days of knee symptoms, and there were no radiographic signs of osteitis or prosthetic loosening. Six of the 16 original total knee arthroplasties (38%) did not need prosthesis removal at a mean follow-up of 64 months (range, 36-151 months). Ten other knees were treated with irrigation, débridement, and hardware removal within 7 weeks of the latest procedure used to try to retain components. Two (13%) of these cases ultimately required an arthrodesis for persistent infection. Although we still believe that this method is preferable to resorting immediately to implant removal for acute infections, arthroscopic débridement was less efficacious for most situations when compared with open treatment. We would use arthroscopic irrigation and débridement only under selected circumstances (medically unstable or anticoagulated patients).

[Therapy of osteonecrosis. Basic principles and decision aids]

The treatment of osteonecrosis of the femoral head involves a continuum based on a radiographic spectrum of disease. Core decompression or pharmacological agents can be utilized for the earliest small or medium-sized pre-collapsed lesions. For these types of lesions, osteotomy has been tried by various authors with moderate success. For small or medium lesions that are post-collapse, various bone grafting procedures have been used. This approach should be tempered with a look at the articular cartilage if this is damaged or the lesion is large. Limited femoral resurfacing can be used for hips that do not have acetabular involvement. If there is acetabular involvement, total hip replacement remains the treatment of choice. There are present innovations in total hip arthroplasty that hopefully will lead to increased longevity of these prostheses with newer polyethylenes as well as the use of ceramic and other types of interfaces. Another possible advance for this disease would be the use of metal on metal standard prostheses, as well as metal on metal resurfacing arthroplasties. In terms of a salvage of the femoral head, all of the different procedures--core decompression, osteotomy, bone grafting--can be enhanced by new advances in the development of the utilization of bioactive factors. These range from osteoinductive agents such as cytokines, angiogenic stimulating factors, and bone morphogenetic proteins. In addition, osteoconductive substances may be helpful and can be combined with osteoinductive substances. These bioactive factors are described in detail in another chapter of this issue. With the ushering in of the millennium, there is hope for better results with this disease.

Management of osteonecrosis in systemic lupus erythematosus

Osteonecrosis is commonly found in patients with systemic lupus erythematosus. The effects of this disease are magnified because these patients commonly have, in addition to hip involvement, multiple other joints involved with the disease. Early diagnosis is important for medical and surgical management to try to avoid total joint replacements in this young patient population. There are many joint salvaging procedures that have had moderate success in patients with this disease. In the future, pharmacologic agents and growth and differentiation factors may be effective in the early treatment of this disease and may lead to more successful outcomes with surgical options.

[Potential uses of cytokines and growth factors in treatment of osteonecrosis]

Osteonecrosis of the femoral head remains a devastating disease for young patients. As the normal process of bone formation, bone destruction, and fracture healing becomes more clearly understood, molecular agents--including cytokines, bone morphogenetic proteins, and angiogenic factors--will be identified as potential therapeutic agents for the treatment of osteonecrosis. As the pathology of osteonecrosis and repair of osteonecrotic lesions becomes clear, the potential combination of these molecular factors to influence the outcome of the disease in its repair process should become evident. With the myriad of agents and combinations of agents which may be beneficial in the treatment of osteonecrosis, a reproducible animal model is urgently needed to determine which of these combinations is most effective. Despite the lack of an animal model, progress in the use of cytokines for osteonecrosis treatment in conjunction with traditional treatment methods is possible in human subjects. This is due to the extremely low incidence of adverse reactions when these cytokines are used locally in nanogram to microgram quantities.

Atraumatic osteonecrosis of the adult elbow

Osteonecrosis is a disease that leads to joint destruction and often involves large joints, such as the hips, knees, and shoulders. Nontraumatic osteonecrosis of the adult elbow, to the best of the authors' knowledge, has not been reported. Nine adult patients with atraumatic osteonecrosis of 11 elbows were identified. The mean age at presentation was 36 years (range, 26-63 years); five patients were women and four were men. Six elbows involved the capitellum, three involved the lateral epicondyles, one involved the trochlea and radial head, and one involved medial and lateral epicondylar disease. All patients were receiving corticosteroid therapy, and no relationship between the duration or the amount of corticosteroid use and the severity of the osteonecrosis was found. Seven patients with radiographic Stage I and Stage II disease responded well to nonoperative treatments consisting of activity modification, analgesics, and a brief period of immobilization. Nonoperative treatment failed in two patients with Stage III disease, and they had core decompressions for pain relief. One patient with late Stage III disease in both elbows underwent bilateral total elbow arthroplasties. In contrast to the pediatric population, osteonecrosis of the adult elbow potentially can lead to end stage arthritis. If the osteonecrosis is diagnosed early, nonoperative treatment may be effective in relieving pain, although the long-term results of these treatments remain unknown.

Cortical strut grafting for enigmatic thigh pain following total hip arthroplasty

Enigmatic thigh pain remains a difficult problem to treat after total hip arthroplasty. This article reports on the use of strut cortical allografting for the treatment of recalcitrant enigmatic thigh pain following total hip arthroplasty in patients with a well-fixed cemented or cementless femoral component.

Clinical experience with a proximally porous-coated second-generation cementless total hip prosthesis: minimum 5-year follow-up

This study reports the minimum 5-year follow-up of our experience with the Porous-Coated Anatomic E (PCA-E) series femoral stem and the modular acetabular cup. A total of 115 consecutive total hip replacements using PCA-E series (Howmedica, Rutherford, NJ) were performed in 108 patients. Six patients whose hips were performing well clinically died before 5-year follow-up and were excluded from the final evaluation. The remaining 109 hips (102 patients) were assessed at a mean follow-up of 72 months (range, 60-84 months). The hip diagnoses were osteoarthritis in 73, osteonecrosis in 31, rheumatoid arthritis in 2, and hip dysplasia in 3. The mean age was 56 years (range, 24-83 years). Three hips were revised: 1 because of late hematogenous infection, 1 because of aseptic loosening of the femoral component, and 1 because of postoperative loosening of an acetabular component. The Harris hip scores improved from a mean of 50 points (range, 20-66 points) preoperatively to a mean of 92 points (range, 64-100 points) at final follow-up. The score differed in each Charnley functional class, with a mean of 93 points (range, 72-100 points) in 57 hips of class A (no other joint involvement); 90 points (range, 58-100 points) in 26 hips of class B (opposite hip involvement); and 85 points (range, 37-100 points) in 26 hips of class C (multiple joint involvement or severe systemic disease). Out of 106 hips that had a full radiographic evaluation performed, 103 femoral components revealed stable bony ingrowth, 2 revealed stable fibrous ingrowth, and 1 showed migration with progressive loosening. This patient with radiographic loosening has minimal symptoms and has not required or been offered further surgery (Harris hip score of 86 points). The low aseptic loosening rate (2%) at minimum 5-year follow-up compares favorably with any cemented or cementless series. The osteolysis that was seen was focal and localized. The short follow-up does not allow determination of progression. There were no cases of distal osteolysis. We attribute the improved results from reported first-generation experience to multiple factors, including increased number of sizes (9 vs 6), increased proportional metaphyseal size, improved polyethylene manufacture (ram extruded vs machined), improved acetabular locking mechanism, and change to 26-mm from 32-mm femoral heads.

Proximally porous-coated ingrowth prostheses: limits of use

Callaghan has suggested that the most important factor in obtaining optimal results after total hip arthroplasty may be the ability to determine when to use cemented or cementless fixation. This article has presented the indications and relative contraindications for use of proximally porous-coated prostheses. Midterm results suggest that with appropriate patient selection, excellent clinical results can be achieved with currently available proximally porous-coated prostheses. Use of proximally coated prostheses is indicated for primary total hip arthroplasty in patients aged >70 years with good bone stock. Relative contraindications are based on interference with bone ingrowth or with the ability to achieve a congruent fit, both of which preclude establishment of rigid initial stability. These conditions include metabolic bone disease such as osteoporosis, osteomalacia, Gaucher's disease, sickle cell disorders, and Paget's disease; significant anatomical distortion, as seen in developmental dysplasia of the hip with anteversion, prior osteotomy, or intertrochanteric fracture; Dorr type C bone; and current treatment with radiation, chemotherapy, indomethacin, or diphosphonates. The same relative contraindications to use are applicable in revision situations. Further, proximally porous-coated prostheses should not be used for revision arthroplasty in the setting of massive bone loss, limited life expectancy, or inability to participate in protected weight bearing. These devices may be used successfully in revision arthroplasty when the hip has minimal or moderate bone loss, and occasionally in the setting of severe bone loss. As further information is revealed through the long-term (10-20 years) results of proximally coated prostheses, further refinements and knowledge of the indications and contraindications for the use of these prostheses will be revealed.

Pathologic features in steroid and nonsteroid associated osteonecrosis

Multiple pathophysiologies for osteonecrosis have been postulated and various associated risk factors defined for this disease. However, the pathologic findings of the end stage disease are thought to be similar in all patients. To the author's knowledge, there are no data in the literature comparing the pathologic characteristics of osteonecrosis in a quantitative manner between groups of patients with different associated risk factors. The current study examined the pathologic features of core decompression specimens from the femoral head in a group of patients with osteonecrosis associated with corticosteroid therapy and compared them with specimens from patients with osteonecrosis with no history of corticosteroid therapy. The study group comprised 65 patients (96 hips); 45 patients (68 hips) in the corticosteroid group and 20 patients (28 hips) in the noncorticosteroid group. In the corticosteroid group, 65% of dead bone was identified histologically (44 of 68) as compared with 46% (13 of 28) in the noncorticosteroid group. Specimens staged according to the histologic grading system of Arlet and Durroux revealed the corticosteroid group had a higher incidence of late stage lesions than did the noncorticosteroid group. This was found even though the two groups had similar radiographic staging distribution. The hips in patients who used alcohol were comparable pathologically to the hips in patients who used corticosteroids. This study emphasizes that the histologic features of necrosis and repair are similar in corticosteroid and noncorticosteroid osteonecrosis. However, there were differences in the distribution of viable bone and pathologic stage of the lesions in the two groups, suggesting a more rapid evolution of changes in the corticosteroid group.

Operative management and outcome of complex wounds following total knee arthroplasty

This study describes the treatment protocol for and the outcome of the management of complex wounds around total knee replacements. An analysis of 28 patients (29 knees) with complex defects who had surgery between January 1, 1986, and July 30, 1996, was performed. A specific management protocol was applied to each knee on the basis of the size and depth of the wound, the presence of infection, and the quality of soft tissue. Primary treatment included local wound care, debridement, and skin grafting or coverage with a fasciocutaneous flap, pedicled muscle flap, or free muscle transfer. Postoperatively, knees were evaluated using the Knee Society objective score. Successful salvage of the lower extremity was obtained in 28 knees (97 percent) and of the knee prosthesis in 24 of 29 knees (83 percent). Secondary plastic surgery procedures were necessary in five knees (17 percent), and secondary orthopedic procedures were necessary in four knees (14 percent). Successful salvage of total knee arthroplasty in the presence of a complex wound requires early identification of infection, aggressive irrigation and debridement, and early appropriate soft-tissue coverage. The use of our proposed algorithm will facilitate management of these complex wounds.