Spinal cord injury is an inevitable but rare occurrence in sports. Identifying trends and working to minimise risk is an integral part of sports management. All patients suffering a spinal cord injury in Scotland will be transferred to the Queen Elizabeth National Spinal Injuries Unit (QENSIU). Our records give an accurate account of trends in spinal cord injury. This study details the number of spinal cord injuries caused by sports and leisure pursuits in Scotland since 1992.

1451 patients have suffered a spinal cord injury in Scotland from 1992-2008. 142 (9.8%) arose from injuries during sport. The average age at injury was 32, and patients were predominantly male (91%). The commonest cause was diving (40, 28%) followed by cycling (29, 20%) climbing and hillwalking (15, 11%) and rugby union (12, 8%). Smaller numbers were seen in horse-riding (11), aerial sports (6), motor sports (6), snow sports (5), and football (5). Overall, there was evidence of an increasing trend in the number and severity of injuries in rugby and cycling.

The number of spinal injuries, caused by diving, rugby and cycling remains disproportionally high and the increasing trends identified merit further investigation.

Purpose

Patients with ankylosing spondylitis (AS) are vulnerable to cervical spine injury following relatively minor trauma. The authors present a retrospective review to determine the characteristics, treatment and outcome following cervical spine injury in these patients.

Patients with spinal injuries are very vulnerable to early complications or secondary spinal cord injuries before and during transfer, which may delay their rehabilitation. We designed transfer guidelines following concerns raised in a pilot study of the transfer of 16 patients. We then examined the effectiveness of the guidelines in 100 consecutive patients and completed the cycle by re-auditing a further 254 consecutive admissions after incorporating changes from the initial audit.

The transfer guidelines addressed ten areas of clinical concern. We recorded a 50% improvement in airway monitoring and management. There was also improvement in anti-ulcer therapy and thromboprophylaxis (from 50% to 96%). We saw a 50% improvement in the use of appropriate support staff during the transfer.

The re-audit showed that initial improvements were maintained and further improvements were noted in the transfer of relevant documentation and investigations. Improvement was also noted in the use of a vacuum mattress for the transfer of spinal injury patients and subsequently reduced incidence of pressure sores by a statistically significant level, which helped in the early rehabilitation of these patients. The majority of transfers were safe.

The transfer guidelines were easy to use and improved patient care by ensuring that common problems had been addressed before and during transfer. This system reduced the risk of preventable complications during inter-hospital transfer. There may be wider application of similar guidelines to other trauma patients who require inter-hospital transfer, where there is a possibility of preventable secondary injury.

After spinal cord injury (SCI) rapid muscle atrophy and extensive bone loss occur in the paralysed limbs resulting in increased fracture incidence (mostly at the epiphyses in the distal and proximal tibia and distal femur). We investigated whether re-introducing mechanical loading of the lower-limb bones in chronic SCI through exercise could induce bone formation, in accordance with Wolff’s Law.

We present cross-sectional data from the Scottish paraplegic population illustrating the time course of bone loss after SCI, and review case studies describing musculoskeletal changes following lower-limb exercise interventions in chronic SCI. Reference data were obtained from 47 subjects with SCI at neurological levels T2 to L2, ranging from 6 months to 40 years post-injury. We used peripheral Quantitative Computed Tomography (XCT3000, Stratec, Germany) to scan 4 sites in the tibia and 2 in the femur, and evaluated trabecular, cortical, and total bone data, and soft-tissue parameters. Here, we focus on trabecular bone mineral density (BMDtrab) at the epiphyses, which provides an indicator of bone integrity. The same scans were performed pre- and post-training in chronic paraplegics who undertook a period of lower-limb exercise training (body-weight-supported treadmill training (BWSTT) or electrically-stimulated leg cycle (FES-cycle) training); these results are reviewed.

The temporal pattern of bone loss is characterised by exponential decline in BMDtrab, reaching steady-state at 100 mg/cm3 in the distal tibia after 7 years and at 130 mg/cm3 in the distal femur after 3 years. A subject with incomplete SCI (18 years post-injury) showed an increase in BMDtrab in the distal tibia following 5-months BWSTT. In a separate study, subjects with complete SCI had varying responses to FES-cycle training.

Bone loss appears to plateau after 7 years post-SCI. The effectiveness of physical interventions aimed at reversing bone loss in chronic SCI seemingly depends on the details of the associated bone-loading patterns.

Metal-on-metal (MOM) hip resurfacing devices are known to release metal ions locally and into the systemic circulation. Previous studies suggest that larger prosthetic head size will correlate to reduced wear properties and may result in lower systemic release of metal ions. This project assessed the effect of femoral head size on serum cobalt (Co) and chromium (Cr) levels in subjects after unilateral hip resurfacing with the Cormet 2000 prosthesis.

We prospectively collected patient characteristics, outcome, and serum samples from device implanted subjects at six months, one, two, and three years following surgery. Serum Co/Cr levels were determined using high-resolution inductively coupled plasma mass spectrometry. Students t-test was used to compare ion levels in two groups based on femoral head size.

Thirty-five subjects (twenty male) were followed. Co/Cr levels were increased at all time points when compared to control levels. A significant negative correlation was observed between Co and Cr levels and femoral head size. Co/Cr levels in subjects with larger femoral heads were significantly lower when compared to those implanted with smaller heads (Co, −35.8%; Cr, −33.0%). This correlated with significantly higher Co/Cr levels in females versus males, with females receiving significantly smaller heads on average.

Elevated serum Co/Cr levels were observed at all time points following implantation and in females and in subjects with femoral heads.

Introduction: Metal-on-metal (MOM) hip resurfacing is becoming a more accepted and available option to consider when treating increasingly younger and more active patients. Advantages include preservation of bone stock and a larger femoral head which increases range of motion without risk of dislocation. We report here the effects of gender on revision rates in patients receiving the Cormet 2000 MOM Hip Resurfacing System.

Methods: 1058 hips were implanted in a multicenter, prospective study. All patients received a cementless, press-fit Cobalt Chrome acetabular shell with plasma sprayed titanium and HA coating and cemented Cobalt Chrome femoral head. Patients were evaluated pre-operatively through 2 years using standardized questionnaires, physical examinations, and radiographic evaluations.

Results: There were 754 males (71%) and 304 (29%) females implanted with the device. Thirty-eight (3.6%) revisions were required; 19 females (6.3%) and 19 (2.5%) males. Males had risk factors significant for revision including increased age in 10-year increments and smaller implant size. Trending but not significant (p=0.08) was lower preoperative HHS.

Discussion and Conclusion: There was a difference in revision rates between males and females, likely due to a difference in bone mass and stability. Based on these findings, the optimal patient seemed to be a larger, younger, more active male. This population has previously been identified to be at most risk after THA and utilization of a resurfacing device may be a good alternative. In addition, future studies designed to optimally select females for MOM hip resurfacing may reduce the revision rate in that population.

Introduction: Metal-on-metal (MOM) hip resurfacing releases ions locally and into the systemic circulation, raising concern for potential long term complications of elevated trace metals. This study was designed to monitor serum cobalt (Co) and chromium (Cr) levels in patients after MOM resurfacing hip arthroplasty with the Cormet 2000 prosthesis and to compare detected levels with those previously reported for hip resurfacing prostheses.

Methods: We prospectively followed patients receiving the Cormet 2000 device. Serum samples were collected at 6 months, 1, 2, and 3 years following surgery. Pre-operative controls were obtained from subjects without implants. Serum Co/Cr levels were determined using high-resolution inductively coupled plasma mass spectrometry. ANOVA was used to compare ion levels in each group. Statistical significance was set at p< 0.05.

Results: 40 subjects (25 male) were followed. Average age was 51 years (33.7–66.1). Median preoperative Co/ Cr levels were 0.27 microg/L (0.087–0.601) and 0.19 (0.014–0.576), respectively. Co/Cr levels were significantly increased at all time points when compared to preoperative levels (p< 0.001). Peak Co and Cr levels were observed at 1 year (3.26 and 4.42, respectively). At three years, the median Co and Cr levels had dropped to 2.08 and 3.55, respectively, but this was not statistically significant.

Conclusion: Elevated serum Co/Cr levels were observed at all time points following implantation. Continued elevations at three years were observed; however, the levels appear to be trending down suggestive of a “wear-in” period. Long term elevations of Co/Cr levels are concerning and will require additional studies to assess long term health risks of these levels in this population.

SEREX was used to identify candidate tumor antigens in the nonimmunogenic fibrosarcoma (NFSA) tumor model. One of the six clones identified was of particular interest. NFSA-5 was identified as the receptor for hylaronan-acid-mediated motility (RHAMM), which is involved in cell growth and metastasis. RHAMM is expressed in a variety of human tumors. RHAMM is differentially expressed, with significant levels not found in normal tissues other than testis, placenta, and thymus. Therefore, RHAMM may be an appealing target for human tumor vaccines. The identification of murine homologs to human tumor antigens may aid in the preclinical development of human tumor vaccines.

The goal of our studies was to use serological analysis of antigens by recombinant expression cloning (SEREX) to identify candidate tumor antigens in a nonimmunogenic murine fibrosarcoma model.

SEREX provides a rapid means of identifying candidate tumor antigens in murine cancer models.

The identification of murine homologs to human tumor antigens may aid in the preclinical development of human tumor vaccines.

The SEREX approach included construction of a cDNA expression library from NFSA tumors followed by immunoscreening of the library with sera from C3H mice growing NFSA tumors. The nucleotide sequence of insert cDNA was determined for positive clones. Sequence alignments were performed with BLAST software on GenBank database.

Six positive clones were identified. Two clones coded for proteins with known expression in normal tissues. Two clones represented heat-shock proteins, known to be upregulated in human and murine tumors. Two of the clones were of particular interest. Clone NFSA-1 was the homolog to NY-REN-58, an antigen previously identified by SEREX analysis of renal cell carcinoma patients. NFSA-5 was identified as the receptor for the hylaronan-acid-mediated motility (RHAMM), which is involved in cell growth and metastasis. RHAMM was recently identified as a leukemia-associated antigen and is expressed in a variety of human solid tumors including renal cell carcinoma, breast carcinoma, and ovarian carcinoma. RHAMM is differentially expressed, with significant levels not found in normal tissues other than testis, placenta, and thymus. Therefore, RHAMM may be an appealing target for human tumor vaccines.

Funding: This study was supported by a grant received from the William E. McElroy Charitable Foundation.

To determine whether sacral chordoma is monoclonal or polyclonal in origin, a new assay to study the polymorphic human androgen receptor locus (HUMARA) was applied. The ratio of maternal inactive X-chromosone to the paternal inactive X (Lyon hypothesis) was determined via a methylation-specific polymerase chain reaction (PCR) technique. Seven of seven informative samples showed a polyclonal proliferation pattern. This study suggests that chordomas are more comparable to mesenchymal neoplasms than to monoclonal hematopoeitic neoplasms.

The purpose of this study was to determine whether sacral chordoma is monoclonal or polyclonal in origin via a new molecular genetic assay of the x-chromosome.

A polyclonal proliferation pattern was identified in all informative samples studied.

Characterization of the genetic tumorigenesis of this unpredictable neoplasm may lend insight into its biological behavior and offer novel therapeutic intervention.

Utilizing a new assay to study the polymorphic human androgen receptor locus (HUMARA), the ratio of maternal inactive X-chromosome to the paternal inactive X (Lyon hypothesis) is determined via a methylation-specific polymerase chain reaction (PCR) technique to detect X-chromosome polymorphisms. Eight female chordoma patients had their DNA harvested and their x-chromosome inactivation pattern and polymorphisms determined and compared to control. A polyclonal proliferation pattern was identified in seven of seven informative samples. The eighth sample showed a single x chromosome allele in normal and tumor tissue and was thus viewed as uninformative.

Infection is one of the major reasons leading to early revision of total hip joint replacements. Traditionally, samples have been taken for microscopy, culture and sensitivity at the time of surgery. However, this doesn’t always reveal a causative organism. Molecular techniques have now been refined to improve sensitivity in bacterial detection.

In this study, samples were taken from acetabular and femoral components at the time of revision hip surgery for suspected infection. These underwent conventional culturing and also PCR and DNA sequencing. The white cell count, CRP and ESR were also recorded.

Results are available for 6 cases. All of these patients had an elevated CRP level (17–169). Microscopy at the time of surgery showed scanty white cells and no organisms on at least 1 sample from 2 cases. Subsequent culture was negative. When sonication techniques were used to remove bacterial DNA, followed by PCR and sequencing, one of these cases yielded Stenomophonas sp. A further 4 cases were positive for Stenophomonas using molecular techniques despite conventional culture being negative.

Stenophomonas sp is a gram negative bacillus. Its ability to adhere to plastic and to produce a bacteraemia are of significance in its proposed role in hip arthroplasty infection. It is also known to be resistant to most commonly used broad spectrum antibiotics.

This study demonstrated that we may be under-diagnosing infection in hip revision patients. These new techniques could prove invaluable in detecting low yet significant levels of bacteria which may lead to a change in current antibiotic policy for joint replacements and subsequently a reduction in the number of revisions required for loosening due to infection.

Substantial bone loss and bone defects are the most challenging problems faced by the surgeon performing revision surgery. Of the many techniques available, impaction bone grafting aims to achieve stability of an implant with the use of compacted, morselized bone graft and subsequently allows restoration of bone stock by bone ingrowth. This technique was proposed with a highly polished double tapered stem. This technique has also been subsequently used with stems of varying surface finish and shape. We report here our experience with impaction grafting using Charnley stem and variants with 8–10 year results assessing the radiological appearance and subsequent behaviour of the impacted allograft.

A prospective radiological study of revision hip arthroplasty done for aseptic loosening with femoral bone loss is presented. Pre operative bone loss was assessed using the Endo Klinik grading system. Impaction grafting with fresh frozen femoral head allograft and the flanged 40 size Charnley stem was used in 17 cases and extra heavey flanged 40 size was used in 9 casaes. Post operative and annual review radiographs were examined for graft distribution, graft consolidation, cortical repair and subsidence of the stem.

Twenty six revisions performed in 25 patients between May 1994 and November 1996 were followed up for 8–10 years. Mean age was 66 years(range 26–83 years). There were eighteen male and 7 female patients. One patient died 2 years and 9 months after the operation. Pre operatively Endo Klinik grade 2 bone loss was seen in 7 cases and grade 3 bone loss was seen in 19 cases. Post operative radiographs showed even graft distribution in twenty cases, five patients had poor filling in Gruen zone 3 and one patient had poor filling in zone 2. All cases demonstrated evidence of graft consolidation by one year. Twenty two cases showed no further changes after 8–10 years. Two cases of subsidence have been revised and one patient is awaiting revision ( 8 years after revision). Two of these were extra heavy flanged 40 stems. Three cases showed subsidence > 5mm and were associated with graft deficiency in zone 2 or 3. Out of these three one had an extra heavy flanged 40 stem inserted. There were no medical complications or deep infection following surgery in these patients. One patient had dislocation.

In conclusion, femoral revision using impaction grafting with the Charnley stem produces satisfactory radiological results in the medium to long term. Good graft distribution on a postoperative radiograph is associated with graft consolidation, cortical repair and minimal stem subsidence. Extra heavy flanged 40 stems perform less satisfactorily compared to the flanged 40 stems. Inadequate graft filling is associated with stem subsidence and revision. These findings highlight the importance of meticulous surgical technique to ensure even graft distribution. This study supports the taper of the Charnley stem and suggests that a vaquasheen finish is not contraindicated.

Low Contact Stress(LCS) total knee arthroplasty was developed to reduce contact stress on the bearing surface and to minimise stresses at the interface between the host bone and the implant surface leading to long term implant survival. The rotating platform was introduced as the bearing interface when both cruciates are sacrificed. It has a central cone which engages into a matching cone in the tibial tray. This allows unconstrained axial rotation of the bearing surface. However, this potentially leaves the platform susceptible to subluxation/dislocation. The reported rate of this complication varies from 0.5% to 4.65%.

In this study from a single center we report the incidence and highlight the associated causative factors found in our series. There were 1053 Low Contact Stress total knee arthroplasties performed between 1994 and 2003. We reviewed 10 knees in 9 patients who had dislocation of the polyethylene rotating platform. This amounts to 0.95% in our series. All the patients with dislocation were women. Average age was 72 years(range 62–84). Osteoarthritis was the primary diagnosis in 8 patients. One patient was suffering from rheumatoid arthritis was on long term steroid therapy and had bilateral dislocations. One patient with Osteoarthritis with Parkinson’s disease went onto have 2 recurrent dislocations. Pre-operative deformity was varus in 9 knees(range 4–10 degrees) and valgus of 15 degrees was noted in one. Time from index operation to dislocation ranged from as early as 10 days to 10 months. There was history of trauma and acute presentation only in one patient. In one patient the knee dislocated while she twisted her knee in bed and in another while climbing up the stairs. In the remaining seven patients the presentation was subacute with symptoms such as pain, decreased range of motion, swelling and a clunking sensation while walking.

Although manipulation under anaesthesia was successful in 3 patients, all of them had recurrent dislocations and two patients had revision to a deepdish platform. Failed closed reduction led to open reduction in two patients with replacement of the rotating platform to deepdish (12.5 mm) type in one. Following both procedures knee was immobilised in a cast for 6 weeks. Five patients were directly revised without attempting closed reduction to a deepdish rotating platform. At revision in all cases the platform was found to be rotated medialy and posteriorly. Soft tissue imbalance and laxity were seen in all but one. At an average followup of 48.5 months (range 11–84 months) no patient had recurrent instability.

Increasing age, questionable soft tissue integrity and varus deformity were significantly associated with rotating platform dislocation. Closed reduction may be possible but invariably leads to recurrence of dislocation and open reduction with revision of the rotating platform gives reliable results. Replacing the rotating platform with a thicker deepdish bearing provides satisfactory stability at revision surgery. Meticulous surgical technique with accurate soft tissue balancing are important in reducing the incidence of dislocations.

Introduction and Aims: The purpose of our study was to review our experience with the use of arthroscopy for the diagnosis and management of patients with problematic total knee replacements (TKRs).

Method: Forty-four patients were retrospectively reviewed to evaluate clinical and diagnostic efficacy of arthroscopy of TKR.

Results: Six patients with soft-tissue impingement had good-excellent outcome. Three patients had lateral retinacular release to correct patellar subluxation. Arthroscopic treatment of infection in two patients with significant comorbidities was able to control infection in one patient. Of the 13 patients with decreased range of motion due to intra-articular scarring, only four maintained increased motion. Of the 20 patients who had arthroscopy as a diagnostic procedure, 15 were successfully diagnosed and treated. Of the 10 patients with knee pain as the primary complaint, an intra-articular cause of the knee pain was identified in five patients and successfully treated in four, while no diagnosis was made in the remaining five patients.

Conclusion: The use of arthroscopy for the diagnosis and treatment of the problematic TKA is an effective and safe procedure when performed for specific indications. We found adhesiolysis of limited value for patients with decreased range of motion due to dense scar tissue.

Introduction: Atypical femoral geometry and bone stock loss may make fitting a press-fit, traditional one-piece stem difficult, if not impossible. Modularity that permits independent fitting of the diaphysis, metaphysis, length, offset, and version may greatly facilitate reconstruction and ultimate clinical performance.

Method: We prospectively evaluated the early clinical results of Exactech’s AcuMatch®^□ M-series prosthesis, a novel three-piece modular femoral stem. One hundred and twenty-seven were implanted in 114 patients. Ninety-one of these were primaries and 36 were revisions. The patients were followed prospectively and evaluated pre-operatively and at ≥2-year post-operatively.

Results: Harris hip score for primaries was 37 pre-operatively and 87 at last follow-up. Harris hip score for revision group was 35 pre-operatively and 84 at last follow-up. Four dislocations occurred and one prosthesis fractured in a 330-pound patient with deficient abductors. One prosthesis has been removed, due to sepsis in the primary group.

Conclusion: Through atraumatic milling of the bone and insertion of the implants, a minimal amount of intra-operative complications resulted. Ultimate restoration of hip biomechanics and soft tissue tension resulted in good clinical outcome with a very low dislocation rate.

Introduction and Aim: The bone preserving aspect of hip resurfacing combined with minimal wear metal-metal technology is a promising solution for the younger patient who requires a hip replacement. The purpose of this study is to evaluate the early outcomes of patients treated with the Cormet 2000 resurfacing hip prosthesis.

Method: All surgical procedures were performed by a single surgeon (DGA). Thirty-two patients, with a mean age of 52.7 years, were prospectively evaluated pre-operatively and at a minimum of one-year follow-up using standardised questionnaires, physical examinations, and radiographic evaluations.

Results: All patients rated their satisfaction with the procedure as good or excellent. Mean Harris hip scores increased from 51 pre-operatively to 92 at last follow-up. Level of pain and ability to perform activities of daily living were significantly improved compared to pre-operative scores. The mean leg length, offset and neck shaft angle were essentially restored to normal. There were no radiographic abnormalities and no significant clinical complications.

Conclusion: The short-term clinical outcome of the Cormet 2000 hip resurfacing prosthesis has been excellent.

Introduction: atypical femoral geometry and bone stock loss may make þtting a press þt traditional one-piece stem difþcult, if not impossible. modularity that permits independent þtting of the diaphysis, metaphysis, length, offset, and version may greatly facilitate reconstruction and ultimate clinical performance. Materials and methods: we prospectively evaluated the early clinical results of exactechñs acumatch? m-series prosthesis, a novel three-piece modular femoral stem. eighty-two were implanted in 80 patients. þfty-three of these were primaries and 29 were revisions. the patients were followed prospectively and evaluated with harris hip scores, range of motion, and complications pre-operatively and at ≥ 1-year post-operatively. Results: Harris hip score for primaries was 37 preoperatively and 84 at last follow-up. Harris hip score for revision group was 37 preopera-tively and 79 at last follow-up. Only one dislocation occurred in the 82 cases, in a patient who was revised for recurrent dislocation with deþcient abductors. There were three minor undisplaced calcar fractures in the primary group that did not alter the clinical outcome and in no case did the prosthesis penetrate the diaphysis. One prosthesis has been removed, and this was due to sepsis in the primary group. Conclusion: Through atraumatic milling of the bone and insertion of the implants, a minimal amount of intra-operative complications resulted. Ultimate restoration of hip biomechanics and soft tissue tension resulted in good clinical outcome with a very low dislocation rate.

Introduction: Whether to resurface or not resurface the patientñs patella at the time of TKA remains controversial. Our goal was to compare outcomes of 148 NexGen Legacy Posterior Stabilized TKAs in which the patella was resurfaced in 71 patients and left unresurfaced in 77 patients. Methods: Patients were followed prospectively and evaluated with Knee Society Scores, Hospital for Special Surgery scores, range of motion, SF12, and complications pre-operatively and at ≥ 2-year postoperatively. Results: There was no signiþcant difference in the Knee Society Function Subscore, range of motion, knee pain at rest, and SF12 scores at last follow-up. There was signiþcantly less knee pain while walking in patients who had their patella resurfaced, however there was no signiþcant difference in anterior knee pain. Hospital for Special Surgery and Knee Society Assessment Subscore were signiþcantly higher in the resurfaced group. One knee in the unresurfaced group was re-operated on with tibia tubercle osteotomy and medial reeþng for recurrent dislocation. This patient had a pre-operatively dislocated patellae. Another patient in the unresurfaced group had an undisplaced patellar fracture that was treated nonoperatively. This patient had extreme erosion of her patella pre-operatively. Conclusion: These results suggest that the innovative design of the NexGen Legacy Posterior Stabilized prosthesis may facilitate leaving the patella unresurfaced if indicated, however, pain scores may be superior with resurfacing.

Aim: To assess the radiological appearance and subsequent behaviour of impacted allograft in revision hip surgery using the Charnley femoral prosthesis. Method: A prospective radiological study of hip arthroplasty revised for aseptic loosening with femoral bone loss was performed. Preoperative bone loss was assessed using the Endo Klinik grading. Impaction grafting with fresh frozen femoral head allograft and the Charnley stem was used in all cases. Postoperative X-rays and annual review films were examined for graft distribution, cortical repair and stem subsidence. Graft consolidation and cortical repair was assessed. Results: Twenty cases were followed up for 6 to 8 years. Fourteen cases had even distribution of graft and 6 had deficiency in one Gruen zone. Graft consolidation was identified in all cases at one year. Cortical repair was noted in 14 out of 15 Endo Klinik III cases. One patient died after 2 years and 9 months. Two stems have subsided by more than 5 mm and are asymptomatic. Two cases with subsidence have been revised. All cases with subsidence were associated with graft deficiency in Gruen zone II or III on the postoperative X-ray. Conclusions: Good initial graft distribution on the postoperative X-ray is associated with graft consolidation, cortical repair and minimal stem subsidence. Initial deficiency in graft distribution is associated with stem subsidence and revision. These findings highlight the importance of a surgical technique, which ensures even graft distribution.

Introduction: while modularity that permits independent fitting of the diaphysis, metaphysis, length, offset, and version may greatly facilitate reconstruction and ultimate clinical performance, potential generation of metallic wear debris due to fretting at the modular interface is a concern. Materials and methods: serum titanium was analyzed using inductively coupled plasma sector field mass spectrometry. titanium levels were analyzed preoperatively and at 1-year follow-up in patients treated with the acumatch^? m-series prosthesis, which has a three-piece modular femoral stem and preopera-tively, at 1-year and 2-year follow-up in patients treated with the versys nonmodular femoral stem. Results: Pre-operative mean serum titanium levels were not significantly different in patients receiving the modular Acumatch (0.25 ppb) or the nonmodular Versys (0.21 ppb) femoral stems. Titanium level in the Acumatch group was significantly higher at 1 year (2.56 ppb; range: 0.65–5.62) than those obtained for the Versys group at 1 year (1.86 ppb: range: 1.08–2.65) or 2 year (1.46 ppb: range: 1.12–2.02) post-operatively (P< 0.05). Titanium levels were significantly increased at each follow-up in both the Acumatch and Versys groups when compared to pre-operative levels (P< 0.001). Discussion/ Conclusion: Serum titanium levels were significantly increased in patients treated with the highly modular Acumatch hip prosthesis when compared to patients treated with the nonmodular Versys femoral stem. The clinical relevance of this finding is currently unknown.