Effects of teriparatide on cementless bipolar hemiarthroplasty in patients with osteoporotic femoral neck fractures.

BACKGROUND: For osteoporotic femoral neck fractures, suitable bone-implant stability is critical for pain relief, early return to daily activities and reduction of complications. Teriparatide (parathyroid hormone [PTH1-34]) can improve bone-implant stability in some basic studies. However it's use in osteoporotic femoral neck fractures treated by cementless hemiarthroplasties for the beneficial effects on bone-implant stability is sparse in the literature. The aim of this study was to determine if post-operative teriparatide administration can reduce femoral stem migration and improve early functional recovery and health-related quality of life (HRQoL). METHODS: Between 2010 and 2014, patients with osteoporotic femoral neck fracture who underwent cementless bipolar hemiarthroplasty were included into this retrospective cohort study. Group A included patients treated with cementless bipolar hemiarthroplasty only; Group B patients had additional teriparatide. Demographic data, complications, radiographic and functional outcomes as well as health-related quality of life (HRQoL) were compared. RESULTS: There were 52 hips in group A (no teriparatide) and 40 hips in group B (patient who received teriparatide). The subsidence of the femoral stem tended to be significantly decreased in the teriparatide group at 6 and 12 weeks post-operatively (p = 0.003 and p = 0.008, respectively). The Harris Hip Score (HHS) increased significantly from pre-operation to 6 weeks post-operatively and thereafter up to one year in both groups. However, there were no significant differences in terms of subsequent fracture, mortality, HHS, and HRQoL between two groups during the entire study period. CONCLUSIONS: Teriparatide significantly reduces the subsidence of the cementless femoral stem in elderly patients in the early post-operative period, but this benefit does not reflect better functional outcomes and HRQoL. Further prospective randomized large-scale cohort study is warranted for evidence-based recommendations.

The Influence of Alignment on Midterm Outcome after Total Knee Arthroplasty in Patients With Marked Coronal Femoral Bowing.

Whether the mechanical axis should be restored to neutral remains controversial when the patient has marked coronal femoral bowing. Eighty-four total knee arthroplasties were retrospectively reviewed. In the neutral-aligned group A the immediate postoperative mechanical axis of 179 ± 1° held stable (P = 0.841). The postoperative mechanical axis decreased from 176 ± 1° to 173 ± 1° (P = 0.024) in the outlier group. Progressive varus in the outlier group at follow-up was probably due implant instability and ligament imbalance as well as excessive polyethylene wear. At a mean follow-up of 75.8 months, no statistically significant difference was detected between the two groups. Long-term follow up will be needed to determine if the maintenance in radiographic results translates to better clinical outcomes.

Comparison of computer-navigated and conventional total knee arthroplasty in patients with Ranawat type-II valgus deformity: medium-term clinical and radiological results.

BACKGROUND: Arthritic knees with Ranawat type-II valgus deformity present with soft tissue contracture and osseous anomalies that make total knee arthroplasty (TKA) difficult. We hypothesized that computer-navigated-TKA (CN-TKA) may be superior to conventional techniques and provide better mid-term radiographic and clinical outcomes in such cases. METHODS: Between January 2002 and January 2009, patients with Ranawat type-II valgus deformity who underwent primary TKA were entered into this retrospective study. Conventional TKA and CN-TKA were compared for the accuracy of component placement, joint line level, and postoperative limb alignment. International Knee Society scores and patellar scores were used for clinical assessment. RESULTS: A total of 62 patients (70 knees) with a minimum of 5 years of follow-up were studied. Conventional TKA was performed in 36 knees and CN-TKA in 34 knees. A significantly higher rate of lateral retinaculum release was recorded in the conventional TKA group compared to the CN-TKA group. Proper restoration of joint line was achieved using CN-TKA. The range of motion of the knees was similar in both groups preoperative and postoperatively. There were no significant differences in reconstructed mechanical axes, accuracy of component positioning, and difference in perioperative hemoglobin level between the two groups. At a mean follow-up of 6.2 years, both groups had significant postoperative improvements in clinical performance, however the difference did not reach statistical significance between both techniques. CONCLUSIONS: Our findings demonstrate that CN-TKA can properly restored the joint line level for arthritic knees with Ranawat type II valgus deformity. However, no differences in clinical function, limb and component alignment, or survival of the prostheses were noted between the CN-TKA and conventional TKA groups at a mean follow-up of 6.2 years.

Detecting Rotator Cuff Tears: A Network Meta-analysis of 144 Diagnostic Studies.

BACKGROUND: Many imaging techniques have been developed for the detection of rotator cuff tears (RCTs). Despite numerous quantitative diagnostic studies, their relative accuracy remains inconclusive. PURPOSE: To determine which of 3 commonly used imaging modalities is optimal for the diagnosis of RCTs. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: Studies evaluating the performance of magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA), and ultrasound (US) used in the detection of RCTs were retrieved from the PubMed/MEDLINE and Embase databases. Diagnostic data were extracted from articles that met the inclusion/exclusion criteria. A network meta-analysis was performed using an arm-based model to pool the absolute sensitivity and specificity, relative sensitivity and specificity, and diagnostic odds ratio as well as the superiority index for ranking the probability of these techniques. RESULTS: A total of 144 studies involving 14,059 patients (14,212 shoulders) were included in this network meta-analysis. For the detection of full-thickness (FT) tears, partial-thickness (PT) tears, or any tear, MRA had the highest sensitivity, specificity, and superiority index. For the detection of any tear, MRI had better performance than US (sensitivity: 0.84 vs 0.81, specificity: 0.86 vs 0.82, and superiority index: 0.98 vs 0.22, respectively). With regard to FT tears, MRI had a higher sensitivity and superiority index than US (0.91 vs 0.87 and 0.67 vs 0.28, respectively) and a similar specificity (0.88 vs 0.88, respectively). The results for PT tears were similar to the detection of FT tears. A sensitivity analysis was performed by removing studies involving only 1 arm for FT tears, PT tears, or any tear, and the results remained stable. CONCLUSION: This network meta-analysis of diagnostic tests revealed that high-field MRA had the highest diagnostic value for detecting any tear, followed by low-field MRA, high-field MRI, high-frequency US, low-field MRI, and low-frequency US. These findings can help guide clinicians in deciding on the appropriate imaging modality.

Iatrogenic radial nerve palsy after operative management of humeral shaft fractures.

BACKGROUND: It is generally agreed that a period of observation is appropriate for primary radial nerve palsy associated with humeral shaft fractures. There is no consensus, however, with regard to secondary radial nerve palsy, particularly when it is iatrogenic. Most texts state that surgical exploration is indicated for nerve palsy that occurs after fracture manipulation, but our experience suggests that it is not necessary for radial nerve palsy developing after operative management of humeral shaft fractures. METHODS: A total of 707 humerus shaft fractures were treated operatively at our two hospitals over a 10-year period. Of these, 30 patients sustained iatrogenic radial nerve palsy. Another 16 cases were referred to us with adequate documentation from other institutions. No recognized intraoperative injuries to the radial nerve were recorded in any case. RESULTS: Of the 46 patients, 21 were female and 25 were male. The median age was 40 years (range, 19-75 years). A total of 39 patients had been treated with dynamic compression plates, 3 with a rigid interlocking intramedullary nail, and 4 with Ender nails. All fractures were diaphyseal, at the middle or distal third level. At the discretion of the surgeon, five cases were surgically explored. In all five cases the radial nerve was in continuity and no macroscopic lesions were noted. All cases eventually recovered grade 4 of 5 muscle strength or better. The median time to the beginning of clinical recovery was 16 weeks (range, 5-30 weeks). CONCLUSIONS: The timing and pattern of radial nerve recovery in this situation was similar to that seen in primary radial nerve palsy. There appears to be no advantage to early exploration of the radial nerve. In the absence of obviously misplaced instrumentation or fracture displacement, we treat it like a primary palsy and recommend observation for a minimum of 4 months before exploration.

Twenty-four-week hospital-based progressive resistance training on functional recovery in female patients post total knee arthroplasty.

BACKGROUND: After total knee arthroplasty (TKA) surgery, a decline in muscle strength is associated with a decrease in function. The aim of this study was to demonstrate the effect of a further 24 weeks of hospital-based resistance training under supervision, and precise dose on knee functional recovery and daily activities for female TKA patients. METHODS: Twenty-nine patients who underwent unilateral primary TKA were allocated into either resistance training (RT) (n = 14) or control (CON) (n = 15) groups. All patients were assessed, with an isokinetic dynamometer, for hip and knee flexor and extensor muscle strength, physical function test, and Knee Injury and Osteoarthritis Outcome Score (KOOS). Resistance training was initiated three months after index surgery. The assessments were performed before exercise (Baseline), in the middle of the resistance training at 12 weeks (Mid-exercise), completion of the resistance training (Post-exercise), and 12 weeks after resistance training completion (Follow-up). A statistical test was performed by using generalized estimating equations. RESULTS: Patients in RT had more of an increase in both knee extensor and flexor muscle strength than those in CON at the Post-exercise assessment. The six-minute walk test distance was more in RT compared with CON at the same Post-exercise assessment. Furthermore, the RT group had increases in Activities of daily living and Sports subscales compared to the CON group. CONCLUSIONS: A further 24 weeks of hospital-based progressive resistance training facilitated improvement in knee muscle strength and functional outcome in TKA patients. Active hospital-based progressive resistance training is recommended for rehabilitation following TKA surgery.

Comparison of computer-assisted navigation and conventional instrumentation for bilateral total knee arthroplasty: The outcomes at mid-term follow-up.

It remains unclear if computer-assisted surgery (CAS) technique actually improves the clinical outcomes of total knee arthroplasty (TKA) and decreases the failure rate. The purpose of this retrospective study was to compare the functional results of TKA in a series of patients who underwent staged bilateral TKAs with CAS TKA in 1 knee and conventional TKA in the contralateral knee.From January 1997 to December 2010, we collected 60 patients who were randomly assigned to receive CAS TKA in 1 limb and conventional TKA in the other. The Brainlab Vector Vision navigation system was used for CAS TKA, and the DePuy press-fit condylar sigma guide system was used for conventional TKA. Patients were assessed before surgery, 3 months and 1 year after surgery, and annually thereafter. IKS criteria were used for radiographic evaluation. Clinical and functional evaluation using the scoring system of hospital for special surgery (HSS), international knee society (IKS), Western Ontario and McMaster University osteoarthritis index (WOMAC), and short form-36 (SF-36) were obtained on each knee, before surgery, and at each follow-up visit. Pertinent statistical methods were adopted for data analysis.Fifty-six patients were available for analysis and 44 of the patients were female. The mean duration of follow-up was 8.1 years. Less blood loss (P = .007) and longer operation time were noted for CAS TKAs when compared with conventional TKAs. Precise alignment and fewer outliers of the lower limb and prosthetic component positions were found for CAS TKAs (P < .001). There were no differences between the 2 groups before surgery and at the latest follow-up with regard to scores for HSS, IKS, WOMAC, and SF-36 as well as active range of motion.The clinical outcomes of CAS TKAs at the 8-year follow-up were similar to those of conventional TKAs despite the better radiographic alignment and fewer outliers achieved with navigation assistance.

The effects of high impact exercise intervention on bone mineral density, physical fitness, and quality of life in postmenopausal women with osteopenia: A retrospective cohort study.

Osteoporosis and osteopenia prevailed in postmenopausal women and predisposed to osteoporotic fractures that increase mortality, morbidity, and the cost of social care. Here, we investigated the effect of 24 weeks of aerobic dancing on the bone miner density, physical fitness and health-related quality of life (HRQoL) in postmenopausal women with osteopenia. Total 80 participants (control [CON]: 40; exercise [EX]: 40) were included in the final analysis. The EX group underwent a 24-week aerobic dance intervention. Bone mineral density (BMD), physical fitness, and SF-36 questionnaire were assessed at baseline and 24-weeks. The BMD change in the femoral neck at the 24-weeks were significantly different between the 2 groups (CON: -1.3 ±â€Š2.7%, EX: 3.1 ±â€Š4.6%, P = .001). Grip strength, sidestep and physical functional domain of HRQoL in the EX group were significantly improved compared to the CON. The results were suggested 24-week aerobic dance intervention could result in the lower the incidence of bone fracture through increasing BMD and decreasing fall risk for postmenopausal women.

Circuit training enhances function in patients undergoing total knee arthroplasty: a retrospective cohort study.

BACKGROUND: The number of patients receiving total knee arthroplasty (TKA) has been rising every year due to the aging population and the obesity epidemic. Post-operative rehabilitation is important for the outcome of TKA. METHODS: A series of 34 patients who underwent primary unilateral TKA was retrospectively collected and divided into either exercise group (n = 16) and control group (n = 18). The exercise group underwent a 24-week course of circuit training beginning 3 months after total knee arthroplasty (TKA). The effect of circuit training on TKA patients in terms of motion analysis, muscle strength testing, Knee injury and Osteoarthritis Outcomes Score (KOOS) questionnaire and patient-reported outcome measurement Short-Form Health Survey (SF-36) at the pre-operation, pre-exercise, mid-exercise, and post-exercise. RESULTS: Motion analysis revealed the stride length, step velocity, and excursion of active knee range of motion significantly improved in the exercise group when compared to those in the control group. KOOS questionnaire showed a greater improvement in pain, ADL, and total scores in the exercise group. The SF-36 questionnaire revealed a significant improvement in general health, bodily pain, social function, and physical components score in the exercise group. CONCLUSIONS: The post-operative circuit training intervention can facilitate recovery of knee function and decrease the degree of pain in the TKA and might be considered a useful adjunct rehabilitative modality. The ultimate influence of circuit training on TKA needs further a prospective randomized clinical trial study and long-term investigation. TRIAL REGISTRATION: NCT02928562.

Teriparatide Improves Fracture Healing and Early Functional Recovery in Treatment of Osteoporotic Intertrochanteric Fractures.

Osteoporotic intertrochanteric fractures result in serious health problems and decrease health-related quality of life (HRQoL). Faster time-to-union is important for early return to daily activities and reduction of complications. Teriparatide has been shown to accelerate fracture healing, but the literature is sparse on this topic. The aim of this study is to assess whether teriparatide accelerates fracture healing.Between 2008 and 2014, patients with osteoporotic intertrochanteric fractures who underwent surgical interventions were enrolled in this retrospective cohort study. Group 1 included patients who were not on any osteoporosis medication prior to fracture and who postoperatively received only calcium and vitamin D; patients in Group 2 were not on any osteoporosis medication prior to fracture, and received teriparatide and calcium and vitamin D postoperatively. Patients in Group 3 were those who were on alendronate prior to fracture and postfracture received teriparatide as well as calcium and vitamin D. Demographics, time-to-union, HRQoL (short-form health survey [SF]-12 physical component summary [PCS] and SF-12 mental component summary [MCS]), morbidities, mortalities, and radiographic and functional outcomes between groups were compared.A total of 189 patients were enrolled in this study. There were 83 patients in Group 1, 47 patients in Group 2, and 59 patients in Group 3. A significantly shorter time-to-union was found in the teriparatide-treated groups (mean, 13.6, 12.3, and 10.6 weeks, respectively [P = 0.002]). With regard to SF-12 PCS, the scores were significantly better in teriparatide-treated groups at 3 months (mean, 19, 28, and 29, respectively [P = 0.002]) and 6 months (mean, 28, 37, and 38, respectively [P = 0.008]). Similar inter-group differences were noted when comparing the pain scores, the ability to get around the house, the ability to get out of the house, and the ability to go shopping at 3 and 6 months. Complications and mortality were also markedly reduced in the teriparatide-treated groups.Postoperative use of teriparatide for 6 months appears to be an effective adjunct therapy in the treatment of patients with osteoporotic intertrochanteric fractures. However, because of the limited power of the study, a prospective, randomized, large-scale cohort study is still required for determining the efficacy of teriparatide.

Cementless total hip arthroplasty and limb-length equalization in patients with unilateral Crowe type-IV hip dislocation.

BACKGROUND: Total hip arthroplasty in patients with unilateral congenital high dislocation of the hip (Crowe type IV) presents many challenges, including the problem of a marked limb-length discrepancy. The purpose of this retrospective study was to analyze the results of total hip replacement with limb-length equalization in these patients. METHODS: From 1988 to 1996, fifty-six patients (forty-seven women and nine men) with unilateral Crowe type-IV dislocation of the hip were treated with a cementless total hip arthroplasty at a mean age of 35.4 years. The preoperative limb-length discrepancy averaged 4.9 cm. Prior to the total hip arthroplasty, forty-eight patients with a limb-length discrepancy of >4.0 cm underwent iliofemoral distraction with use of an external fixator for eight to seventeen days. The acetabular cup was placed in the anatomical position in every patient. Shortening femoral osteotomies were not required. RESULTS: The iliac fixator pins loosened in six patients. No patient had a pin-site infection, hip joint infection, or nerve palsy. At the time of follow-up, at an average of 147.2 months, the Harris hip score averaged 90.2 points. Overall, the mean lengthening after the total hip arthroplasty was 4.6 cm. There were no revisions of the femoral stem. Nine cups were revised, four because of polyethylene wear and five because of loosening. CONCLUSIONS: We were able to safely place the acetabular cup at the anatomical position without femoral shortening by bringing the femoral head to the normal level preoperatively; thus, we could restore nearly normal limb length. We believe that our twelve-year results are similar to those of total hip arthroplasty in patients without dysplasia.

The use of alendronate to prevent early collapse of the femoral head in patients with nontraumatic osteonecrosis. A randomized clinical study.

BACKGROUND: Osteonecrosis of the femoral head is the most common diagnosis leading to total hip arthroplasty in young adults. Joint-preserving treatment options have been mainly surgical, with inconsistent results. Alendronate (a bisphosphonate agent) has been shown to lower the prevalence of vertebral compression fractures and could potentially retard the collapse of an osteonecrotic femoral head. The purpose of this study was to test the effect of alendronate in preventing early collapse of the femoral head in patients with nontraumatic osteonecrosis. METHODS: Forty patients with Steinberg stage-II or III nontraumatic osteonecrosis of the femoral head and a necrotic area of >30% (class C) were randomly divided into alendronate and control groups of twenty patients each. Patients in the alendronate group took 70 mg of alendronate orally per week for twenty-five weeks, while the patients in the control group did not receive this medication or a placebo. The patients were observed for a minimum of twenty-four months. Harris hip scores, plain radiographs, and magnetic resonance imaging scans were obtained. RESULTS: During the study period, only two of twenty-nine femoral heads in the alendronate group collapsed, whereas nineteen of twenty-five femoral heads in the control group collapsed (p < 0.001). One hip in the alendronate group underwent total hip arthroplasty, whereas sixteen hips in the control group underwent total hip arthroplasty (p < 0.001). CONCLUSIONS: Alendronate appeared to prevent early collapse of the femoral head in the hips with Steinberg stage-II or IIIC nontraumatic osteonecrosis. A longer duration of follow-up is needed to confirm whether alendronate prevents or only retards collapse. LEVEL OF EVIDENCE: Therapeutic Level I.

Anterior subtalar dislocation: a case report.

Anterior subtalar dislocations are extremely rare. To our knowledge, six cases have been reported in detail in the literature, but for only two of these was an anteroposterior view radiograph used to confirm the diagnosis. We report a case of anterior subtalar dislocation in which the posterior tibialis tendon was incarcerated in the talonavicular joint and that required an open reduction. We discuss the diagnosis, mechanism, and treatment.

Improved femoral component rotation in advanced genu valgum deformity using computer-assisted measured resection total knee arthroplasty.

BACKGROUND: Accurate femoral rotational alignment is of vital importance for successful total knee arthroplasty (TKA). The value of computer-assisted surgery TKA (CAS-TKA) in increasing the accuracy of femoral rotational alignment remains controversial. We hypothesize that outcomes are related to the severity of preoperative varus and valgus deformity and that CAS-TKA may be beneficial under certain circumstances. METHODS: Between January 2007 and December 2013, patients with osteoarthritis and varus angulation in the mechanical axis (MA) ≥ 15° and valgus angulation in the MA ≥ 10° (based on hip-to-ankle standing radiography) who underwent TKA were divided into four groups. CAS-TKA and conventional TKA outcomes were compared in patients who had preoperative advanced genu varum and advanced genu valgum deformities. The accuracy of component alignment and postoperative limb alignment was determined using radiographic parameters and computed tomography (CT). RESULTS: One hundred and eight patients (144 knees) were included in the analysis. For patients with preoperative advanced genu varum deformity, a significant difference was detected in the sagittal femoral angle (p < 0.001), but no significant improvement of femoral rotational alignment was noted (p = 0.127). In patients with preoperative advanced genu valgum deformity, a significant difference was found in the sagittal femoral angle (p = 0.034). The femoral rotational angle was significantly closer to the proper position in the CAS-TKA group (p < 0.001). When comparing the percentage of knees achieving the proper alignment, there was a decrease in the amount of outlier for the femoral rotational angle for CAS-TKA in advanced genu valgum deformity (p = 0.011). CONCLUSIONS: Our data demonstrate that CAS-TKA is beneficial in obtaining proper femoral rotational alignment in patients with advanced genu valgum deformity (preoperative MA ≥ 10° valgus). In patients with advanced genu varum deformity (preoperative MA ≥ 15° varus), CAS-TKA did not improve the femoral rotational alignment.

Variability of distal femoral valgus resection angle in patients with end-stage osteoarthritis and genu varum deformity: Radiographic study in an ethnic Asian population.

BACKGROUND: When performing a total knee arthroplasty, most surgeons use the intramedullary alignment guide with a fixed distal femoral valgus resection angle. In this study, we assessed the variability of the distal femoral valgus resection angle in ethnic Asian patients by reviewing our arthroplasty database. METHODS: Between January 2004 and December 2012, the patients with end-stage osteoarthritis with genu varum deformity who underwent total knee arthroplasty were enrolled in this retrospective review. Clinical and radiographic data were collected and analyzed. RESULTS: Nine hundred and fifty-two knees met the inclusion criteria. Three hundred and four (31.9%) knees had a distal femoral valgus resection angle value outside the range of 5° ±2° (range, 4°-14°). There were significant differences in the mean distal femoral valgus resection angle between males and females (p < 0.001) and between non-bowed femur and bowed femur (p < 0.001) cohorts. With regard to the correlation coefficients between the distal femoral valgus resection angle and the usual radiographic measurements, only the coronal femoral bowing angle demonstrated a good correlation (r = 0.72). CONCLUSIONS: 32% of Asian patients present with a distal femoral valgus resection angle that is outside the range of 5° ±2°. Taking a long-leg weight-bearing split scanogram may provide information that allows the surgeon to determine the true distal femoral valgus resection angle and adjust the cut accordingly. LEVEL OF EVIDENCE: Therapeutic level III.

Ionic versus nonionic paramagnetic contrast media in differentiating between postoperative scar and recurrent disk.

BACKGROUND AND PURPOSE: In theory, ionic solutes diffuse more slowly in cartilage than do nonionic solutes. We tested the hypothesis that the contrast ratio between scar and recurrent disk fragment on MR images is greater after IV administration of an ionic rather than a nonionic contrast medium when a clinical dose is used. METHODS: Twenty patients who had recurrent lumbar disk herniation were enrolled in this study. The enhancement of epidural scar and recurrent disk fragment was measured at 5, 25, 40, and 50 min after IV injection of ionic and nonionic contrast media (0.1 mmol/kg) RESULTS: The enhancement was consistently and significantly higher for scar than for recurrent disk fragment, although the contrast ratio between scar and recurrent disk fragment decreased between 5 and 50 min after the administration of each contrast medium. No significant difference was shown between ionic and nonionic contrast media in the enhancement of recurrent disk fragment at 5, 25, 40, and 50 min after injection. The contrast ratio between scar and recurrent disk fragment was not a significant difference at 5, 25, and 40 min after administration of both contrast media. At 50 min, the contrast ratio between scar and recurrent disk fragment was 1.32 +/- 0.41 with ionic contrast medium and 1.20 +/- 0.56 with nonionic contrast medium. The difference was significant. CONCLUSION: The contrast ratio between scar and recurrent disk fragment is affected by the timing of the imaging. Images obtained immediately after the injection of each contrast medium showed a greater contrast ratio than did delayed images. In addition, with the ionic medium, this difference was greater than with nonionic medium at 5, 25, 40, and 50 min after injection and that difference reached statistical significance at 50 min.

Failure of hydroxyapatite-coated acetabular cups. Ten-year follow-up of 85 Landos Atoll arthroplasties.

Between March 1990 and May 1991 we performed 85 primary total hip replacements in 74 patients using the Landos Atoll hydroxyapatite (HA)-coated cup and the Corail HA-coated stem. The patients were followed up for a mean of ten years. Of the 85 cups, 26 (31%) have already been revised and a further six are radiologically unstable and awaiting revision. Two femoral stems have been revised for infection without loosening. The retrieved acetabular cups were studied by SEM and image-processing techniques to quantify the amount of residual HA on the cup. This was correlated with the clinical variables and modes of failure. The residual HA (as a percentage of the surface) on the loose cups correlated negatively with the duration of implantation (r = -0.732, p < 0.001). Six cups were stable at revision and had more residual HA coating than those which were loose (p < 0.01). The rate of failure of the Landos Atoll HA-coated, smooth hemispherical cup with screw fixation is unacceptably high. Resorption of the HA coating is markedly increased in loose cups compared with stable cups. HA coating cannot substitute for stable mechanical fixation.

Spontaneous cervical intradural disc herniation associated with ossification of posterior longitudinal ligament.

Intradural herniation of a cervical disc is rare; less than 35 cases have been reported to date. A 52-year-old man with preexisting ossification of posterior longitudinal ligament developed severe neck pain with Lt hemiparesis while asleep. Neurological exam was consistent with Brown-Séquard syndrome. Magnetic resonance images showed a C5-6 herniated disc that was adjacent to the ossified ligament and indenting the cord. The mass was surrounded by cerebrospinal fluid signal intensity margin, and caudally the ventral dura line appears divided into two, consistent with the "Y-sign" described by Sasaji et al. Cord edema were noted. Because of preexisting canal stenosis and spinal cord at risk, a laminoplasty was performed, followed by an anterior C6 corpectomy. Spot-weld type adhesions of the posterior longitudinal ligament to the dura was noted, along with a longitudinal tear in the dura. An intradural extra-arachnoid fragment of herniated disc was removed. Clinical exam at 6 months after surgery revealed normal muscle strength but persistent mild paresthesias. It is difficult to make a definite diagnosis of intradural herniation preoperatively; however, the clinical findings and radiographic signs mentioned above are suggestive and should alert the surgeon to look for an intradural fragment.

The benefits of computer-assisted total knee arthroplasty on coronal alignment with marked femoral bowing in Asian patients.

BACKGROUND: Mechanical alignment guides are designed to compensate for variations in the valgus alignment angle; however, these guides may not be adequate when a patient has coronal alignment with marked bowing deformity. Previous study demonstrates better radiographic results, but the clinical benefits are a matter of speculation. The aim of this study was to investigate whether radiographic benefits of computer-assisted surgery total knee arthroplasty (CAS-TKA) would translate to clinical outcomes. METHODS: Patients with osteoarthritis and coronal alignment with marked bowing deformity who underwent total knee arthroplasty (TKA) at our institution between January 2005 and June 2012 were entered into this retrospective study. Patients were divided into three groups: patients with coronal alignment with marked bowing deformity treated with CAS-TKA; with coronal alignment with marked bowing deformity treated with conventional TKA; and without marked coronal bowing deformity treated with conventional TKA. The computer-assisted navigation and the conventional technique were then compared by radiographic parameters. The International Knee Society (IKS) scores and patellar score were obtained for all patients preoperatively and at the last follow-up visit. RESULTS: One hundred and thirty-seven patients (198 knees) met the inclusion criteria. For patients with osteoarthritic knees with marked femoral bowing deformity, the reconstructed mechanical axis (MA) was significantly closer to normal in the CAS-TKA group (P = 0.002) than in the conventional group. Significant differences in the reconstructed MA after conventional TKA were noted between patients without bowing and those with bowing (P = 0.003). Using the patellar score and IKS score, at a mean follow-up of 52.2 months, the differences did not achieve statistical significance among the three groups. CONCLUSIONS: CAS-TKA was an effective alternative for obtaining proper alignment in patients with coronal alignment with marked bowing deformity. However, there was no statistically significant difference in clinical function between patients treated with CAS-TKA and conventional TKA. Long-term follow-up will be needed to determine if the improvement in radiographic results translates to better clinical outcomes.

Management of partial traumatic hemipelvectomy.

Partial traumatic hemipelvectomy is a devastating condition. Although by definition the affected limb is not totally transected from the trunk because of retained soft tissue, the reported mortality rate is actually higher than in complete traumatic hemipelvectomy. Between January 2000 and December 2011, a total of 917 patients were admitted to the authors' institution for pelvic fracture. Seven of these patients met the criteria for partial traumatic hemipelvectomy. All 7 patients had multiple associated injuries and met the criteria for Baskett class IV hypovolemic shock on arrival at the emergency department. The amount of bleeding was the greatest issue, and control of hemorrhage and rapid blood transfusion were the initial goals. Abdominal aorta balloon occlusion, laparotomy and packing, and pelvic external fixation were useful to control bleeding. Two patients died during the initial resuscitation phase. Angiography (digital subtraction or computed tomographic) was performed in 4 patients but did not provide any treatment-altering information. Limb preservation was attempted in 2 patients; both of these patients eventually required hindquarter amputation. One patient died, and the second patient survived after a difficult postoperative course. The best results were obtained in 3 patients who underwent completion of the hindquarter amputation within 24 hours of trauma. All patients became wheelchair dependent, and no patient was able to return to work. Early completion of hindquarter amputation after hemorrhaging has been controlled is recommended in patients with partial traumatic hemipelvectomy. Angiography did not prove useful in decision making.