Long-Term Survival of Total Hip Arthroplasty Using Implants From Different Manufacturers.

BACKGROUND: Total hip arthroplasty (THA) can be performed using either femoral and acetabular components provided by the same manufacturer (matched components) or components from different manufacturers (unmatched components). We hypothesized that there would be no difference in outcomes following the use of unmatched compared to matched components. METHODS: Data from a nationwide joint registry, the New Zealand Joint Registry (NZJR), were analyzed to assess long-term outcomes of using unmatched implants in THA. RESULTS: The NZJR has recorded a total of 108,613 primary THAs. We excluded combinations with less than 50 implantations, leaving 99,732 arthroplasties (90.5%). The unmatched group consisted of 24,537 (24.6%) THAs. Revision procedures were required in 3434 (4.6%) of the matched group, at a rate of 0.72/100 component years and 1078 (4.4%) of the unmatched group, a rate of 0.69/100 component years (P = .049). THAs with metal-on-metal or ceramic-on-metal bearings were overrepresented in the matched group. When analysis was repeated with these implants excluded, there was no longer a difference in revision rate between groups (4.0% revisions, 0.65/100 component years and 4.3% revisions, 0.67/100 component years [P = .742]). Survival analysis showed 17-year survival for matched components and unmatched to be within 95% confidence intervals at all time points. There was a small, statistically significant improvement in Oxford Hip Scores for the unmatched group compared with the matched group. CONCLUSION: Data from the NZJR confirm that the use of unmatched components in THA has no adverse effect on outcomes.

A Comparative Outcome Study of Hamstring Versus Tibialis Anterior and Synthetic Grafts for Deltoid to Triceps Transfers.

PURPOSE: To assess elbow extension strength and complications after deltoid-triceps transfers using hamstring tendon graft compared with tibialis anterior and synthetic tendon grafts. METHODS: A retrospective review of deltoid-triceps transfers in patients with tetraplegia performed between 1983 and 2014. RESULTS: Seventy-five people (136 arms) had surgery performed, with the majority undergoing simultaneous bilateral surgery (n = 61; 81%). Tibialis anterior tendon grafts were used in 68 arms, synthetic grafts in 23 arms, and hamstring tendon grafts in 45 arms. The average age at surgery was 31 years. Sixty-three arms (46%) were assessed between 12 and 24 months after surgery. Seventy percent of the group (n = 54) were able to extend their elbow against gravity (grade 3 of 5 or greater) following surgery. Seventy-nine percent of those with hamstring grafts achieved grade 3 of 5 or more compared with 77% with tibialis anterior and 33% with synthetic grafts. There was a statistically significant difference in postsurgery elbow extension between the tibialis anterior group and the synthetic graft group and the hamstring and the synthetic graft group but not between the tibialis anterior and the hamstring group. Complications occurred in 19 arms (14%), the majority occurring immediately after surgery and associated with the wounds. The remaining complications were with the synthetic graft group in which dehiscence of the proximal attachment occurred in 30% of the arms. CONCLUSIONS: Autologous tendon grafting is associated with achievement of antigravity elbow extension in a greater proportion of individuals than with prosthetic grafting. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Tendon Transfer Surgery for People With Tetraplegia: An Overview.

After cervical spinal cord injury, the loss of upper limb function is common. This affects an individual's ability to perform activities of daily living and participate in previous life roles. There are surgical procedures that can restore some of the upper limb function lost after cervical spinal cord injury. Tendon transfer surgery has been performed in the tetraplegic population since the early 1970s. The goals of surgery are to provide a person with tetraplegia with active elbow extension, wrist extension (if absent), and sufficient pinch and/or grip strength to perform activities of daily living without the need for adaptive equipment or orthoses. These procedures are suitable for a specific group, usually with spinal cord impairment of C4-8, with explicit components of motor and sensory loss. Comprehensive team assessments of current functioning, environment, and personal circumstances are important to ensure success of any procedure. Rehabilitation after tendon transfer surgery involves immobilization for tendon healing followed by specific, targeted therapy based on motor learning and goal-orientated training. Outcomes of tendon transfer surgery are not limited to the improvements in an individual's strength, function, and performance of activities but have much greater life affects, especially with regard to well-being, employment, and participation. This article will provide an overview of the aims of surgery, preoperative assessment, common procedures, postoperative rehabilitation strategies, and outcomes based on clinical experience and international published literature.

The effects of aging on upper limb tendon transfers in patients with tetraplegia.

PURPOSE: To evaluate the effects of aging on hand function among patients with tetraplegia who had forearm tendon transfer surgery between 1982 and 1990. METHODS: The study used a longitudinal cohort design that compared hand function outcomes in 2012 with those obtained 11 years earlier. A digital analyzer was used to measure key pinch and grip strength, and results were compared with those obtained in 2001 to determine changes in strength over time. The study also evaluated changes in participant's employment status, wheelchair use, and subjective changes in function using the Lamb and Chan questionnaire. RESULTS: Participants had a mean key pinch strength force between 11.5 N (tenodeses) and 32.9 N (active transfers) and grip strength forces between 23 N (tenodeses) and 59 N (active transfers). Since 2001, people with active transfers either maintained strength or experienced decreased strength of 5% to 14%. Thumb tenodesis power decreased 40% to 51%, whereas finger tenodeses power increased 32% to 70%. Three activities in the Lamb and Chan questionnaire were identified by the majority of participants as being worse or much worse over the past 11 years. These were performing a pressure relief and propelling a manual wheelchair on level ground and up a ramp. These findings correspond with the increased number of participants who used a power wheelchair in 2012 (64%) compared with 2001 (26%). Close to half of the participants (46%) were employed compared with the 90% in 2001. CONCLUSIONS: Tendon transfers continued to provide pinch and grip function for individuals with tetraplegia for many years following spinal cord injury. The decrease in strength of those with active transfers over the 11-year period was within the reported aging loss for the normal population. The small number of participants with tenodesis, however, limited our ability to draw meaningful conclusions for this group. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic III.

Osteotomy and unicompartmental knee arthroplasty converted to total knee arthroplasty: data from the New Zealand Joint Registry.

We reviewed the revision rate and functional outcome of all patients who had a total knee arthroplasty (TKA) after an osteotomy or unicompartmental knee arthroplasty (UKA) on the New Zealand Joint Registry. We used these data to compare the results with primary TKA scores, including comparison of age-matched subgroups. There were 711 patients who had undergone TKA as salvage for a failed osteotomy with a revision rate of 1.33 per 100 component years and a mean 6-month Oxford Knee Score (OKS) of 36.9. There were 205 patients who had a failed UKA converted to TKA with a revision rate of 1.97 per 100 component years and a mean OKS of 29.1. The revision rates of TKA for both failed osteotomy and failed UKA were significantly poorer than after primary TKA (0.48 per 100 component years). The mean OKS after revision of a UKA was significantly poorer than both primary TKA and TKA for a failed osteotomy. There was no significant difference in mean OKS between primary TKA and TKA for a failed osteotomy, even among patients younger than 65 years. Revision of a failed osteotomy to a TKA has improved functional results compared with revision of a failed UKA. However, both yield poorer survivorship rates compared with primary TKA.

The relationship between the American Society Of Anesthesiologists physical rating and outcome following total hip and knee arthroplasty: an analysis of theNew Zealand Joint Registry.

BACKGROUND: The purpose of this study was to review the results of the first four years of use of the American Society of Anesthesiologists (ASA) physical status rating system in the New Zealand Joint Registry. Our hypothesis was that patients with a higher ASA score would have an increased mortality rate, an increased early revision arthroplasty rate, and poorer clinical outcomes at six months after total hip or knee arthroplasty. METHODS: We prospectively evaluated the preoperative ASA classes for all patients in the registry who underwent primary total hip or knee arthroplasty from 2005 to 2008 with regard to the six-month mortality rate and the Oxford Hip and Knee Scores at six months. Survival curves were constructed with use of revision joint replacement as the end point. RESULTS: Twenty-two thousand six hundred patients who underwent total hip arthroplasties and 18,434 patients who underwent total knee arthroplasties were recorded in the New Zealand Joint Registry. The six-month mortality rate was 0.77% following hip arthroplasty and 0.40% following knee arthroplasty. Significant differences were observed in the mortality rate between all ASA classes following hip arthroplasty (p < 0.001). Similarly, significant differences were observed in the mortality rate between ASA classes after knee arthroplasty, except between ASA classes 1 and 2 and between ASA classes 3 and 4. The mortality rate was significantly higher (p < 0.001) following hip arthroplasty compared with knee arthroplasty. A significant difference (p < 0.001) in Oxford scores was observed when ASA class 1 and ASA class 2 were compared with ASA class 3 and ASA class 4, independent of age and sex, following both hip or knee arthroplasty. A significant difference was observed in the rate of early revision (revision less than two years after the index procedure) following total hip arthroplasty when ASA class 1 (hazard ratio, 1.39 [95% confidence interval (CI), 1.04 to 1.95]; p = 0.015) and ASA class 2 (hazard ratio, 1.24 [95% CI, 1.02 to 1.55]; p = 0.030) were compared with ASA class 3, which was independent of age and sex. No significant difference was observed in the rate of early revision after total knee arthroplasty. CONCLUSIONS: The ASA physical status score can be used as a predictor of postoperative mortality and functional status following both hip and knee arthroplasty and may predict early failure of total hip arthroplasty necessitating revision. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Bilateral total joint arthroplasty: the early results from the New Zealand National Joint Registry.

This study evaluated the mortality rate, major complications, and early outcomes of single anesthetic bilateral total hip and knee arthroplasty compared with unilateral and staged procedures. A total of 37,828 total hip and knee arthroplasties were evaluated with 6-month Oxford 12 scores. Major complications and mortality rates were recorded. Analysis of variance tables were used for statistical analysis. The single anesthetic bilateral group were significantly younger (P < .001), with their age-adjusted postoperative Oxford 12 scores significantly better (P < .001) than the other 2 groups. The surgeons involved, in general, performed more than 25 total knee and hip arthroplasties per year. There was 1 death within the first 6 months occurring in the staged bilateral group and was unrelated to the surgery. The complication rate as reported by patients was low in all groups, and there was no significant difference. The results show that, in selected patients, single anesthetic bilateral total knee or hip arthroplasty is a safe, low-risk procedure with very good patient-generated outcome scores at 6 months when performed by an experienced surgeon.

Measurement issues related to upper limb interventions in persons who have tetraplegia.

Measurement of upper limb function in persons with tetraplegia poses significant issues for clinicians and researchers. It is crucial that measures detect the small but significant improvements in hand function that may or may not occur as a result of our interventions. Before determining how we measure changes from upper limb interventions, we must establish what outcomes are of greatest interest, and for whom. Many issues have an impact on both the measurement and interpretative process.

A New Zealand national joint registry review of 202 total ankle replacements followed for up to 6 years.

BACKGROUND AND PURPOSE: There have been few reports of large series of ankle replacements. The aim of this study was to document and evaluate the early results of a nationwide series of total ankle replacements (TARs) performed using second- and third-generation implants. METHODS: Records of total ankle replacements performed between February 2000 and November 2005 were retrieved from the New Zealand National Joint Registry and retrospectively reviewed at a mean of 28 months after the primary procedure. At 6 months post surgery, patient scores were generated from questionnaires. Comparisons between patient scores and categorical variables were made using ANOVA. Regression analyses using Cox proportional-hazards modeling were performed to determine predictors of failure. A Kaplan-Meier survivorship curve was used to describe the rate of prosthetic survival. RESULTS: 202 total ankle replacements were performed in 183 patients. 14 prostheses (7%) failed. The overall cumulative 5-year failure-free rate was 86%. An unfavorable patient score at 6 months after the initial procedure turned out to be a good predictor of subsequent failure. The cumulative 5-year failure-free rate was 65% at 5 years for patients with an unfavorable score, and 95% for those who had a favorable patient score. Each 1-point increase in the patient score (i.e. poorer outcome) corresponded to a 5% relative increase in the risk of failure (p < 0.05). In addition, longer operative time for the primary procedure was found in the group of TARs that subsequently failed (p < 0.05). INTERPRETATION: The National Joint Registry appears to be a useful tool for monitoring the trends in TAR surgery.

Successful antimicrobial therapy and implant retention for streptococcal infection of prosthetic joints.

BACKGROUND: Streptococci cause up to 20% of prosthetic joint infections but this has received little attention in the published literature. METHODS: We reviewed retrospectively our experience with treatment of streptococcal prosthetic joint infections. Patients were followed up for up to 15 years after discontinuation of antimicrobial therapy and up to 8.5 years while on continuous antimicrobial therapy. RESULTS: Eighteen cases were diagnosed between 1984 and 1995. These included one group A, seven group B, one group D, seven group G and one viridans-group streptococcal infection as well as one group B and D streptococcal co-infection. All were late-onset infections and most (11 of 18, 61%) were acute. Hip and knee joints were equally affected. Six of seven group G streptococcal infections were associated with skin or soft tissue infections. Sixteen patients were treated primarily with antimicrobial agents including 5 days to 6 weeks given intravenously and 2 weeks to 8.5 years given orally. At latest follow up, 10 patients had been off antimicrobial therapy for at least 18 months without relapse, one patient had been off antimicrobial therapy for 7 months without relapse and four infections were successfully controlled with long-term suppressive antimicrobial therapy. One infection was unable to be controlled with antimicrobial therapy. CONCLUSIONS: Our results, and those of others, show that prosthetic joint infections caused by streptococci have a relatively good outcome with primary antimicrobial therapy and, when necessary, drainage, lavage or debridement. Provided the prosthesis is stable and the patient can tolerate long-term antimicrobial therapy, this may be an effective alternative to excision arthroplasty.

Upper limb surgery for tetraplegia: a 10-year re-review of hand function.

PURPOSE: To perform a 10-year re-review of hand function outcome for 24 tetraplegic persons who had received bilateral tendon transfers and tenodeses. METHODS: The Lamb and Chan questionnaire with additional questions, the Quadriplegic Index of Function (QIF), the Swanson sphygmomanometer technique for hook grip, the Preston Pinch Meter (PP) for key pinch, and a digital analyzer (DA) for both hook and key pinch were the test instruments used. The QIF and DA had not been used previously. RESULTS: Levels of functional independence and expectations were maintained. Mean hook grip values were maintained for the right hand but increased significantly for the left to reach right hand values. Mean pinch grip values decreased significantly. DA measurements confirmed similar hook grip values for both hands but key pinch values were significantly higher than the PP values. Active transfers averaged approximately twice the strength of tenodeses. CONCLUSIONS: Hand function improvements gained from tendon transfers and tenodeses are maintained over time.

Analysis of posterior deltoid function one year after surgical restoration of elbow extension.

PURPOSE: The purpose of this study was to measure the extent and timing of elbow extension torque recovery after posterior deltoid-to-triceps tendon transfer. METHODS: Elbow extension moment was measured in 40 limbs from 23 patients who underwent surgical restoration using the posterior deltoid-to-triceps tendon transfer at times ranging from 8 weeks to 1 year after surgery. For comparison purposes, elbow extension moment also was measured in healthy controls and persons with C7 spinal cord injuries. RESULTS: Maximum extension moment was 5.89 +/- 0.24 Nm (mean +/- standard error of mean, n = 40), which corresponds to approximately 65% of the predicted posterior deltoid force and provided an adequate moment to oppose gravity. Based on the shape of the moment-joint angle curve and using a biomechanical model, it was predicted that posterior deltoid was inserted at a relatively short muscle length of 123.1 mm and thus operated exclusively on the ascending limb of the length-tension relationship. CONCLUSIONS: These observations support an evolving model of muscle architecture in which connective tissue septa restrict muscle fiber elongation during surgical tensioning of the tendon transfer. This relatively short length would result in a significant force loss should any of the repair sites slip or stretch during rehabilitation. These data have implications for the reconstruction and rehabilitation of this patient population.