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.

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.

Is single-anaesthetic bilateral primary total hip replacement still safe? A 16-year cohort study from the New Zealand Joint Registry.

BACKGROUND: The surgical management options for bilateral hip osteoarthritis comprise staged or single-anaesthetic bilateral total hip replacements (THRs). The key issue of contention in performing the latter remains safety. We compared unilateral, staged bilateral and single-anaesthetic bilateral THR with the hypothesis that there would be no difference between these three practices using mortality risk, functional outcome and revision rate as the primary outcome measures. METHODS: We performed a retrospective cohort analysis of the New Zealand Joint Registry identifying all primary THRs performed between 1 January 1999 and 31 December 2015. We report this study in accordance with STROBE and RECORD guidelines. We identified all unilateral THRs, all single-anaesthetic bilateral THRs and all staged bilateral THRs and compared the mortality risk, all-cause revision risk with Kaplan-Meier survival analysis and reasons for revision and functional outcome using the Oxford 12 scores. Analysis was adjusted for age, gender, American Society of Anesthesiologists rating score and body mass index. RESULTS: The mortality risk for single-anaesthetic bilateral THR within 3 months was 0.26% and for unilateral THR 0.75% (hazard ratio 0.35 (95% confidence interval (CI) 0.30-0.41, P < 0.001). The risk of revision in the single-anaesthetic bilateral THR group was 0.69/100 component years (95% CI 0.59-0.79/100 component years) versus 0.74/100 component years (95% CI 0.72-0.77/100 component years) in unilateral THR. Mean Oxford 12 scores at 6 months post-arthroplasty was 41.7 (95% CI 41.2-42.2) in the single-anaesthetic bilateral THR group. The best results in the staged bilateral THR group were obtained if the second procedure was delayed by at least 90 days from the first THR. CONCLUSIONS: Single anaesthetic bilateral THR is at least as safe as unilateral THR or staged bilateral THR in appropriately selected cases. Experienced surgeons can expect predictable survival rates and functional scores.

Rehabilitation after total joint replacement: a scoping study.

PURPOSE: The evidence supporting rehabilitation after joint replacement, while vast, is of variable quality making it difficult for clinicians to apply the best evidence to their practice. We aimed to map key issues for rehabilitation following joint replacement, highlighting potential avenues for new research. MATERIALS AND METHODS: We conducted a scoping study including research published between January 2013 and December 2016, evaluating effectiveness of rehabilitation following hip and knee total joint replacement. We reviewed this work in the context of outcomes described from previously published research. RESULTS: Thirty individual studies and seven systematic reviews were included, with most research examining the effectiveness of physiotherapy-based exercise rehabilitation after total knee replacement using randomized control trial methods. Rehabilitation after hip and knee replacement whether carried out at the clinic or monitored at home, appears beneficial but type, intensity and duration of interventions were not consistently associated with outcomes. The burden of comorbidities rather than specific rehabilitation approach may better predict rehabilitation outcome. Monitoring of recovery and therapeutic attention appear important but little is known about optimal levels and methods required to maximize outcomes. CONCLUSIONS: More work exploring the role of comorbidities and key components of therapeutic attention and the therapy relationship, using a wider range of study methods may help to advance the field. Implications for Rehabilitation Physiotherapy-based exercise rehabilitation after total hip replacement and total knee replacement, whether carried out at the clinic or monitored at home, appears beneficial. Type, intensity, and duration of interventions do not appear consistently associated with outcomes. Monitoring a patient's recovery appears to be an important component. The available research provides limited guidance regarding optimal levels of monitoring needed to achieve gains following hip and knee replacement and more work is required to clarify these aspects. The burden of comorbidities appears to better predict outcomes regardless of rehabilitation approach.

Rates of Joint Replacement Surgery in New Zealand, 1999-2015: A Comparison of Rheumatoid Arthritis and Osteoarthritis.

OBJECTIVE: To determine rates of joint replacement for people with rheumatoid arthritis (RA) and osteoarthritis (OA) and to examine the characteristics of those receiving elbow replacements. METHODS: Data were extracted from the New Zealand Joint Registry from 1999 to 2015 and annual rates calculated. RESULTS: Rates of joint replacement increased over time for OA but not RA. Elbow replacement was the only procedure performed more commonly in RA. CONCLUSION: There has been a substantial increase in joint replacement for OA in New Zealand. For RA, where access to biologics has been limited to those with erosions, joint replacement rates have not declined, with the exception of elbow replacements.

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.

Survival outcomes of cemented compared to uncemented stems in primary total hip replacement.

Total hip replacement (THR) is a successful and reliable operation for both relieving pain and improving function in patients who are disabled with end stage arthritis. The ageing population is predicted to significantly increase the requirement for THR in patients who have a higher functional demand than those of the past. Uncemented THR was introduced to improve the long term results and in particular the results in younger, higher functioning patients. There has been controversy about the value of uncemented compared to cemented THR although there has been a world-wide trend towards uncemented fixation. Uncemented acetabular fixation has gained wide acceptance, as seen in the increasing number of hybrid THR in joint registries, but there remains debate about the best mode of femoral fixation. In this article we review the history and current world-wide registry data, with an in-depth analysis of the New Zealand Joint Registry, to determine the results of uncemented femoral fixation in an attempt to provide an evidence-based answer as to the value of this form of fixation.

Current trends and projections in the utilisation rates of hip and knee replacement in New Zealand from 2001 to 2026.

AIM: This study aimed to estimate the demand for total hip (THR) and knee replacements (TKR) by 2026 within New Zealand (NZ) and show how demographic factors are likely to influence this projection. METHOD: Yearly population data from the NZ Census was compared to the NZ Joint Register from 2001-2011 and ethnic and gender specific data was organised into 5 year age groups from 35 years to calculate the incidence for each age group. Poisson regression analysis was used to project the incidence for 2026 and to evaluate the independent associations between age, gender and ethnicity. RESULTS: Between 2001 and 2011 the incidence of THR and TKR increased by 8.20% and 52.20% respectively with a peak incidence in the 70-74 age group. Men were less likely to undergo both THR and TKR (OR 0.91, 95% CI 0.89-0.94 and OR 0.88, 95% CI 0.89-0.90). By 2026 the absolute number of THR and TKR is estimated to increase by 84% (8950 procedures) and 183% (8613 procedures) respectively. Europeans were the most likely to undergo THR compared to Maori, Pacific people or Asians (OR 0.72, 95% CI 0.67-0.74). There was a large increase in the age standardised incidence of TKR for Pacific people and they were more likely to undergo TKR than Europeans (OR 1.00, 95% CI 0.97-1.04). CONCLUSION: Over the past decade, incidence of THR and TKR have increased, and by 2026, the number of THR and TKR is projected to increase by 84% and 183% respectively. This increase will create a significant socioeconomic burden which will necessitate prudent and focused healthcare strategies to ensure that there are adequate resources to meet this demand.

Does orthopedic training compromise the outcome in total hip arthroplasty?

BACKGROUND: This study compares the outcomes of total hip arthroplasty surgery performed by a consultant with those performed by supervised and unsupervised orthopedic trainees. METHODS: We reviewed 6 years of patient data from the New Zealand Joint Registry in patients undergoing total hip arthroplasty comparing the outcome measures of revision surgery and Oxford hip score at 6 months with the experience of the primary surgeon. RESULTS: Over the study period 35,415 patients underwent elective total hip arthroplasty; 30,344 performed by a consultant, 2982 by a supervised trainee and 1067 by an unsupervised trainee. There was an overall revision rate of 0.77 per 100 component years. The revision rate was 0.75 (95% confidence interval [CI] 0.68-0.82) for consultants, 0.97 (95% CI, 0.72-1.28) for supervised trainees and 0.70 (95% CI, 0.36-1.22) for unsupervised trainees with no significant differences. There was no significant difference in the reason for revision surgery between the 3 groups. CONCLUSIONS: The mean Oxford hip score was higher for consultants at 40.70 compared with 38.95 and 38.27 for supervised and unsupervised trainees respectively. These results are reassuring and indicate orthopedic training does not adversely compromise arthroplasty patient outcomes.

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.

A multinational assessment of metal-on-metal bearings in hip replacement.

There is emerging evidence that many metal-on-metal (MoM) bearings, when used with large femoral heads in conventional hip replacement and some resurfacing prostheses, are associated with increased rates of revision arthroplasty. Registries are the main sources of data on MoM prostheses. At the recent International Consortium of Orthopaedic Registries (ICOR) meeting, data were presented from the Australian, England and Wales, and New Zealand registries. All registries reported an increased rate of revision for large femoral head MoM prostheses when prostheses were aggregated compared with the aggregated data of hip prostheses with other bearing surfaces. There was also evidence, however, that the outcome varied, depending on the type of prostheses used, in both large femoral head MoM conventional hip replacement as well as resurfacing hip replacement.The relevance of the recent isolated case reports on systemic metal toxicity was also discussed at the ICOR meeting. Although systemic metal toxicity appears to be a rare occurrence, there is a need to undertake appropriately designed studies to define the true prevalence of this phenomenon. There may be advantages in nesting these studies within registries. The ICOR meeting highlighted the implications of the MoM experience for the orthopaedic industry, regulators, and surgeons.

Use of patient-reported outcomes in the context of different levels of data.

There is increasing interest in measuring patient-reported outcomes as part of routine medical practice, particularly in fields like total joint replacement surgery, where pain relief, satisfaction, function, and health-related quality of life, as perceived by the patient, are primary outcomes. We review some well-known outcome instruments, measurement issues, and early experiences with large-scale collection of patient-reported outcome measures in joint registries. The patient-reported outcome measures are reviewed in the context of multidimensional outcome assessment that includes the traditional clinical outcome parameters as well as disease-specific and general patient-reported outcome measures.

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.

Shared care between geriatricians and orthopaedic surgeons as a model of care for older patients with hip fractures.

AIMS: To evaluate the effect of shared care between geriatricians and orthopaedic surgeons as a model of care for older patients with hip fractures. METHODS: All patients over the age of 65 years are under the shared care of an orthopaedic surgeon and geriatrician (the Ortho-Medicine Service) when they are admitted to the Orthopaedic Service, Christchurch Hospital, New Zealand. This retrospective case records audit includes all patients over the age of 65 years with hip fracture admitted to this service over a 6-month period from December 2002 to June 2003. RESULTS: There were 150 patients. The median age was 83 years (range 66-99 years). Median total length of stay was 23 days. Median time delay until theatre was 43.5 hours. Inpatient mortality was 0.7%. Of 97 patients admitted from home, 86(88.6%) returned home, 6 (6.2%) went to rest home care, and 5 (5.2 %) went to hospital level care. Of 43 patients admitted from rest home care, 40 (93%) returned to rest home care, and 3 (7.0 %) were discharged to hospital level care. Three patients admitted from rest home dementia care and six patients admitted from hospital level care were discharged back to their pre-morbid place of domicile. At discharge, 86.8% of patients were on Vitamin D supplementation and over 80% were on calcium. Only 10.6% were discharged on bisphosphonates. CONCLUSIONS: Shared care between geriatricians and orthopaedic surgeons for older people with hip fractures is associated with a low in-patient mortality, with the majority returning to their pre-morbid place of domicile. Length of stay has increased. Most patients are discharged on treatment for osteoporosis.