Pelvic position, lying on a traction table, during THA by direct anterior approach. Comparison with the standing position and influence on the acetabular cup anteversion.

INTRODUCTION: The placement of prostheses for a total hip arthroplasty (THA) is essential to limit complications and optimize functional results. In a recent study of more than 100 THA placed through a direct anterior approach using a traction table, we found that the mean anteversion of the cup was greater (30°) than recommended (20°). To explain this phenomenon, we considered that the anterior pelvic plane (APP), defined by the plane passing through the anterior-superior iliac spines and the pubic symphysis, which serves as a landmark for the placement and calculation of the anteversion of the cup, was not horizontal when the patient was lying on the traction table. This concept has not been evaluated so we conducted a prospective study to: 1) measure the position of the pelvis on a traction table; 2) compare to the standing position, 3) assess its impact on the anteversion of the cup. HYPOTHESIS: The standing pelvic version is identical to the supine pelvic version on the traction table. MATERIAL AND METHODS: A prospective 3-month monocentric study was conducted. All patients operated on for a THA by a direct anterior approach, on a traction table, were included. The position of the pelvis was assessed by measuring the tilt of the APP on lateral pelvic X-rays, while on the traction table and while standing. The impact of the position of the pelvis on the positioning of the cup, as well as the anteversion, were measured using the EOS imaging system. The anatomic anteversion of the cup was measured in relation to the APP. RESULTS: Fifty-eight patients were included (32 women, 26 men) with an average age of 67 years. The tilt of the supine APP was 6°±8.3 [range of -10.5 to 31.0] (indicating a retroverted pelvis on the traction table). The difference between the tilt of the standing and lying APP (within 90°) was not significant (standing was on average 4.5° [range of -11.0 to 27.0] versus lying on the table, was on average 6° [range of -10.5 to 31.0] (p=0.75). A strong correlation was observed between the tilt of the supine APP and the anatomic anteversion of the cup (p<0.001). Thus, the more retroverted the pelvis was on the traction table, the lower the anatomic anteversion of the acetabular cup. CONCLUSION: The supine pelvis on the traction table is not always horizontal and its position on the traction table is similar to its standing position, within 90 degrees. The analysis of the positioning of the preoperative pelvis appears to be essential in the planning of a THA through direct anterior approach using a traction table. LEVEL OF EVIDENCE: IV; Prospective Cohort Study.

Total hip arthroplasty via the anterior approach: tips and tricks for primary and revision surgery.

PURPOSE: Described for the first time in the 1950s, the direct anterior approach to the hip has been gaining in popularity over the last decade following the trend of minimally invasive surgery. This paper provides an overview of the approach and its indications and various uses and focuses on its utility in the revision setting. A detailed overview of the technique including tips and tricks as well as an explanation of common errors are included. METHOD: Graphic and clinical study of the approach, indications and feasibility. RESULTS: The reported benefits of the direct anterior technique include enhanced post-operative recovery and respect for all the innervation and vascularization territories. It has been shown to be safe and effective in revision settings, to decrease the occurrence of heterotopic ossification, to enhance the accuracy of acetabular cup positioning, and to improve post-operative rehabilitation while having comparable outcomes in terms of loosening or component failure. Additionally, thromboembolic events have been shown to be decreased compared to other approaches. The most common reported complications in the revision setting is intra-operative fracture. The decision of a surgeon to transition to this approach, however, comes with a learning curve and potentially detrimental complications if done improperly. DISCUSSION: In addition to its appeal in the primary setting, the approach could possibly be a solution to decrease the morbidity associated with revision surgery through its use of a fresh tissue plane not previously traumatized with the primary approach.

Anterior approach for total hip arthroplasty conversion of hip fusion.

PURPOSE: Hip fusion conversion has shown mixed results, in particular a higher rate of failure than primary total hip replacement. Conversion is usually carried out by a lateral approach. METHODS: We reported a series of 37 hip fusion conversions performed by an anterior approach. Clinical and radiographic outcomes of this unusual approach were reported at eight years of follow up. RESULTS: At eight years of follow up, survivorship was 86. 6 % (IC 95 %: 62.4-95.7 %). Sixteen patients reported good relief of the pre-operative back spine or knee pain. PMA score was significantly improved. Two implant aseptic loosenings needing revision surgery were reported. CONCLUSION: The anterior approach seemed to be as good as the other hip approaches for hip fusion conversion to total hip replacement.

A controlled, comparative study of a fixed-bearing versus mobile-bearing ankle arthroplasty.

BACKGROUND: Total ankle arthroplasty is available with fixed-bearing (FB) or mobile-bearing (MB) versions, and there is little consensus on the benefits and drawbacks of each type. This study aimed to compare clinical outcomes of statistically paired series of FB and MB versions of the same ankle prosthesis. METHODS: The study was a multicenter retrospective comparison between 2 groups: the FB group of 33 consecutive Talaris cases and the MB group of 33 "paired" Salto cases, selected from a database of 313 consecutive cases to statistically match etiology, age, and preoperative American Orthopaedic Foot & Ankle Society (AOFAS) score. All patients were operated upon with the same operative technique and received identical pre- and postoperative clinical and radiographic assessments. The mean follow-up was 24 months for the FB group and 23 months for the MB group. RESULTS: There was no statistical difference between results of the 2 groups in terms of accuracy of positioning, clinical and radiographic mobility, and morbidity. The most recent postoperative AOFAS scores were higher for the FB group than for the MB group (P = .05). Radiolucent lines were observed in 4 FB patients versus 13 MB patients (P = .02). Subchondral cysts were noted in 1 FB patient and in 8 MB patients (P = .01). CONCLUSION: There was no notable difference in clinical performance of the FB and MB implants with the numbers available. This short-term study demonstrated that FB ankle arthroplasty had results equivalent to, if not better than, MB ankle arthroplasty. Longer follow-up is necessary to determine the success of this new generation of ankle arthroplasty. LEVEL OF EVIDENCE: Level III, retrospective case control study.

Genetic analysis of glycopeptide-resistant Staphylococcus epidermidis strains from bone and joint infections.

Glycopeptide-resistant Staphylococcus epidermidis (GRSE) strains are of increasing concern in bone and joint infections (BJIs). Using multilocus sequence typing and multilocus variable-number tandem repeat analysis, we show that BJI-associated GRSE strains are genetically diverse but arise from related, multiresistant hospital sequence types (STs), mostly ST2, ST5, and ST23.

Heterotopic ossification of the shoulder after central nervous system lesion: indications for surgery and results.

BACKGROUND: Heterotopic ossification (HO) of the shoulder after central nervous system damage has seldom been studied. MATERIALS AND METHODS: We performed a single-center retrospective study from 1993 to 2009 including patients who underwent surgery for troublesome shoulder HO. Demographic data, HO location, surgical approach, preoperative and postoperative shoulder range of motion, etiologies, and postoperative complications were collected from patients' files. RESULTS: We found 19 shoulder HOs in 16 patients (traumatic brain injury in 11, spinal cord injury in 2, stroke in 1, and cerebral anoxia in 2). The data in 2 files were incomplete and were therefore not used. HO locations around the joint were anteroinferomedial in 4 (21.1%), posteroinferomedial in 5 (26.3%), encircling in 3 (15.8%), superior in 1 (5.3%), and mixed (2 associated HOs that are not encircling) in 6 (31.6%). The surgical approaches were as follows: deltopectoral, 5 (26.3%); Neer, 3 (15.8%); posterior, 5 (26.3%); axillary, 1 (5.3%); Martini, 2 (10.5%); posterior associated with deltopectoral, 2 (10.5%); and Neer (superolateral) associated with deltopectoral, 1 (5.3%). The mean range of motion increased significantly (gain at follow-up of 69°, 60°, and 13° in forward elevation, abduction, and lateral rotation, respectively). Regarding postoperative complications, there was 1 case of capsulitis and 1 reoperation for insufficient excision (because of hemorrhage during surgery). There were no other side effects. CONCLUSION: Anatomic relations with nerves and vessels, as well as limited range of motion, require a case-by-case surgical approach, a preoperative scan (looking for a gutter), and sometimes, electromyography. Surgical indications depend on the degree of loss of function or hygiene, control of comorbid factors, and discussion with the patient and his or her family.

Risk factors predictive of chronic postsurgical neuropathic pain: the value of the iliac crest bone harvest model.

Nerve lesions and secondary hyperalgesia may both be present after surgery, and their relative contributions to chronic postsurgical neuropathic pain (CPSNP) remain unclear. This prospective study explored the roles of these factors in the development of CPSNP after iliac crest bone harvest. CPSNP was defined as pain in the area of hypoesthesia, with a positive Douleur neuropathique 4 questionnaire (DN4) score 3 months after iliac crest bone harvest. The location, intensity, and neuropathic characteristics of pain were evaluated in 82 patients who were followed for 6 months. Neuropathic characteristics were assessed by clinical examination and DN4 questionnaire. The area of secondary hyperalgesia was evaluated 48 h and 1 month after surgery. The area of mechanical hypoesthesia, detection, and mechanical pain threshold were evaluated at 48 h and at 1 and 3 months. Nineteen patients (23%) had CPSNP at 3 months. The patients who developed CPSNP had a larger area of secondary hyperalgesia at 48 h (88 cm(2) vs 33 cm(2); P=.001), higher pain intensity (numerical rating scale 6.7 vs 4.7; P=.02), and higher neuropathic characteristics score on the DN4 questionnaire (4.3 vs 2.3; P=.001). However, neither the area nor the severity of hypoesthesia differed significantly between patients with and without CPSNP. Two independent, additive predictors of CPSNP were identified: area of secondary hyperalgesia (odds ratio 1.02; P=.004) and DN4 score (odds ratio 1.94; P=.001). These findings suggest that both nerve lesions and central sensitization are involved in CPSNP development and could be seen as early warning signs.

Troublesome heterotopic ossification after central nervous system damage: a survey of 570 surgeries.

BACKGROUND: Heterotopic ossification (HO) is a frequent complication after central nervous system (CNS) damage but has seldom been studied. We aimed to investigate features of HO for the first time in a large sample and the rate of early recurrence of HO in terms of the time of surgery. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively analyzed data from an anonymous prospective survey of patients undergoing surgery between May 1993 and November 2009 in our institution for troublesome HO related to acquired neurological disease. Demographic and HO characteristics and neurological etiologies were recorded. For 357 consecutive patients, we collected data on 539 first surgeries for HO (129 surgeries for multiple sites). During the follow-up, recurrences requiring another surgery appeared in 31 cases (5.8% [31/539]; 95% confidence interval [CI]: 3.8%-7.8%; 27 patients). Most HO requiring surgery occurred after traumatic brain injury (199 patients [55.7%]), then spinal cord injury (86 [24.0%]), stroke (42 [11.8%]) and cerebral anoxia (30 [8.6%]). The hip was the primary site of HO (328 [60.9%]), then the elbow (115 [21.3%]), knee (77 [14.3%]) and shoulder (19 [3.5%]). For all patients, 181 of the surgeries were performed within the first year after the CNS damage, without recurrence of HO. Recurrence was not associated with etiology (p = 0.46), sex (p = 1.00), age at CNS damage (p = 0.2), multisite localization (p = 0.34), or delay to surgery (p = 0.7). CONCLUSIONS/SIGNIFICANCE: In patients with CNS damage, troublesome HO and recurrence occurs most frequently after traumatic brain injury and appears frequently in the hip and elbow. Early surgery for HO is not a factor of recurrence.

The Salto total ankle arthroplasty: survivorship and analysis of failures at 7 to 11 years.

BACKGROUND: Despite the appearance of new-generation, mobile-bearing, cementless prostheses, total ankle arthroplasty remains controversial. Among the criteria guiding the choice between arthrodesis and arthroplasty, the long-term survival and postoperative function are of critical importance. The mobile-bearing Salto prosthesis has been used in Europe since 1997, but only 2 to 5 years of followup data have been reported. QUESTIONS/PURPOSES: We analyzed the longer-term survivorship and causes of failures of the Salto prosthesis in a cohort of previously studied patients. We asked whether this prosthesis provided a functional ankle (AOFAS score) and durable radiographic fixation. PATIENTS AND METHODS: We retrospectively reviewed 96 prospectively followed patients with 98 prostheses implanted between 1997 and 2000. Of those, 85 patients (87 prostheses) had a minimum followup of 6.8 years (mean, 8.9 years; range, 6.8-11.1 years). RESULTS: The survival rate was 65% (95% CI, 50-80) with any reoperation of the ankle and 85% (95% CI, 75-95) with revision of a component as the end points. Six prostheses were removed for arthrodesis, and 18 ankles underwent reoperation without arthrodesis. We observed three main causes of reoperations: bone cysts (11 patients), fracture of the polyethylene (five patients), and unexplained pain (three patients). The mean AOFAS score was 79 ± 12 points. Radiographic subsidence was observed in three patients and bone cysts in eight patients. CONCLUSIONS: Our data suggest a high rate of reoperations but only six revisions with arthrodesis with mid-term followup. We observed few patients with loosening and/or subsidence. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Decreased susceptibility to teicoplanin and vancomycin in coagulase-negative Staphylococci isolated from orthopedic-device-associated infections.

We studied 315 coagulase-negative Staphylococcus strains recovered prospectively during 240 surgical procedures (206 subjects) from proven or suspected device-associated bone and joint infections. Sixteen strains (5.1%) had decreased susceptibility to glycopeptides: 15 (12 S. epidermidis strains, 2 S. capitis strains, and 1 S. haemolyticus strain) to teicoplanin alone (MIC of 16 mg/liter, n = 9; MIC of 32 mg/liter, n = 6) and one (S. epidermidis) to both teicoplanin and vancomycin (MIC, 16 and 8 mg/liter, respectively). Decreased susceptibility to teicoplanin was more prevalent in "infecting" strains (i.e., strains recovered from >/=2 distinct intraoperative samples) than in "contaminants" (i.e., strains not fulfilling this criterion) (8.1% [12/149] versus 2.4% [4/166], respectively [P = 0.022]). One hundred percent (13/13) of S. epidermidis strains with decreased susceptibility to teicoplanin were resistant to methicillin (versus 112/173 [64.7%] for S. epidermidis strains susceptible to teicoplanin; P = 0.021).

In vivo kinematics of the salto total ankle prosthesis.

BACKGROUND: Recent technological advancements in total ankle arthroplasty (TAA) have included the introduction of the mobile bearing concept. This bearing has several advantages, but researchers have questioned whether or not increased mobility sacrifices joint stability or durability of the implant. The present study evaluated the kinematics of this type of prosthesis implanted in patients. MATERIALS AND METHODS: Fluoroscopy and 3D-to-2D registration techniques were used to determine the in vivo kinematics for 20 TAA subjects performing two activities: gait and step-up. The motion of the prostheses was described in terms of clinical rotations and as rotation about the helical (screw) axis. Then, the anterior-posterior translation and axial rotation of the mobile bearing insert were determined. RESULTS: Among the clinical rotations, the dorsi-/plantarflexion was the most dominant, revealing the greatest pattern change and the largest magnitude. During gait, the orientation of the prosthetic components changed smoothly from plantarflexion to dorsiflexion. The average range of this motion was 9.2 degrees. For step-up activity, the range was 8.0 degrees. However, between 33% and 66% of stance phase, the talar component's orientation changed from dorsiflexion to plantarflexion. The average absolute range of anterior-posterior translation of the mobile bearing insert was 1.5 mm and 2.3 mm for gait and step-up, respectively. CONCLUSION: These measured translations were relatively small and may suggest that the rotational portion of the motion was more dominant than translational and provided sufficient mobility.

Ankle replacement versus arthrodesis: a comparative gait analysis study.

BACKGROUND: The improving survivorship of ankle replacements is making this an increasingly popular option in the treatment of ankle arthritis, rather than the established option of ankle fusion. The potential benefits of restoring movement, improving gait and protecting adjacent joints are persuasive arguments in favor of replacing rather than fusing the ankle joint. METHODS: Gait analysis was performed before and after ankle arthroplasty on 12 patients, and compared to 12 patients with a successful ankle arthrodesis and to a healthy control group of 12 people. RESULTS: Important differences between the arthrodesis and ankle replacement groups were demonstrated although neither restored normal movement or walking speed. Ankle arthrodesis resulted in a faster gait with a longer step length compared to replacement, although the timing of gait demonstrated greater asymmetry. The ankle replacement group had greater movement at the ankle, a symmetrical timing of gait and restored ground reaction force pattern. CONCLUSION: The improved timing of gait would support the observation of a reduction in limp with ankle replacement though the gait is significantly slower. Longer term results are necessary to determine whether the improved movement and force transmission persists with time and protects adjacent articulations.

Treatment of knee flexion contracture due to central nervous system disorders in adults.

BACKGROUND: Studies concerning adult patients with spastic flexion contracture of the knee are rare. Such patients frequently have cutaneous and vascular complications as well as recurrence of the contracture after treatment. We present a strategy consisting of simultaneous correction of all deformities of both lower limbs, distal hamstring releases, and application of femorotibial external fixation when extension of the knee is limited by excessive posterior soft-tissue tension. METHODS: A consecutive series of fifty-nine patients (ninety-seven knees) between the ages of twenty-one and seventy-seven years received surgical treatment for a flexion contracture of the knee secondary to neurological impairment. The flexion contracture was bilateral in thirty-eight patients. Preoperatively, the mean flexion contracture angle was 69 degrees and the mean passive range of motion was 61 degrees. The contracture was corrected, through medial and lateral approaches, with distal hamstring lengthening. A posterior capsulotomy was performed in thirty-five knees. Full extension of thirty-four knees was achieved intraoperatively. In seventy-seven knees, partial correction was maintained with a unilateral external fixator, and passive and active mobilization was performed four times daily after temporary removal of the spanning external fixator rod. RESULTS: At the time of final follow-up, ranging from one to five years postoperatively, the mean residual flexion contracture was 6.2 degrees. Forty-five knees had complete extension, and thirty-nine knees had a residual flexion contracture of <10 degrees. No recurrence of the flexion contracture or instability was noted in any knee at the time of follow-up. There were four cutaneous complications but no vascular or neurological complications. CONCLUSIONS: We believe that our surgical strategy for correction of fixed knee flexion contracture in adult patients is safe and effective. The correction improves nursing care and sitting posture, facilitating the upright position of patients who are unable to walk, and improves walking ability for patients who are able to walk.

Acetabular reconstruction in revision hip surgery using femoral head block allograft.

This prospective study analyzed the clinical and radiological results of 140 consecutive cases of acetabular revision using large frozen femoral head allografts and cemented all-polyethylene acetabular components. Mean follow-up was 10 years (range: 5-16 years). Thirty patients died, seven were lost to follow-up, and 26 had failed and undergone further surgery. Nineteen failures were due to aseptic failure and collapse of the graft. Kaplan-Meier survival analysis calculated a mean survival at 10 years of 88.5% for revision for any reason. We compared all reported techniques of acetabular reconstruction for similar defects and recommend a surgical strategy based on the available evidence, but weighted towards a preference to reconstitute bone stock rather than removing further bone in the revision situation.

Acetabular component revision with frozen massive structural pelvic allograft: average 5-year follow-up.

We evaluated the use of a hemipelvic acetabular transplant in 20 revision hip arthroplasties with massive acetabular bone defects. We report 65% good intermediate-term results at a mean follow-up of 5 years (4-10 years). A cemented cup (without a reinforcement ring) was entirely supported by the allograft in all procedures. There were 7 failures (5 aseptic loosening and 2 deep infections). Two dislocations occurred but did not require acetabular revision. There were 2 cases in which moderate acetabular migration occurred but then stabilised and did not progress. Thirteen of 20 acetabular reconstructions did not require revision. We believe that these are satisfactory intermediate-term results for massive acetabular defects too large for reconstruction with other standard techniques.