Modular Versus Nonmodular Femoral Necks for Primary Total Hip Arthroplasty.

In total hip arthroplasty (THA), proximal femoral neck stem modularity (PFNSM) has theoretical advantages over nonmodular stems, including the ability to more closely reconstruct anatomy and improve stability. However, risks of metallosis and breakage at the junction must be considered. In this study, we compared the head centers of a modular neck system with that of its nonmodular counterpart. Of 463 primary THAs with a modular stem, 261 (56%) had a head center equivalent to that of its nonmodular counterpart, and an additional 132 (29%) had a head center within 4 mm in length and 2 mm of offset. Thus, only 70 stems (15%) had a head center that was more than 4 mm in length and more than 2 mm in offset different from the nonmodular stem. Only 12 stems had a verted neck. These findings suggest that, in a majority of primary THAs, use of a modular stem results in head center positions also achievable with a nonmodular stem. Given the risks of modularity, PFNSM should be used with caution. We recommend PFNSM in cases that cannot be reconstructed with the nonmodular option.

Failure of total hip arthroplasty secondary to infection caused by Brucella abortus and the risk of transmission to operative staff.

Infection of total knee or hip arthroplasty by Brucella species is a rare complication. We describe the case of a failed hip replacement secondary to infection by Brucella abortus, as well as presentation, treatment course, and 2-year follow-up. In addition, we review the literature for features of periprosthetic Brucella species infections, and we describe the common exposures, clinical presentations, preoperative evaluation, and treatments used in the reported cases. Furthermore, we discuss the risk of transmission to operating room personnel and the appropriate preventative measures to avoid transmission.

Primary Total Knee Arthroplasty in Super-obese Patients: Dramatically Higher Postoperative Complication Rates Even Compared to Revision Surgery.

This study utilized a national database to evaluate 90 day postoperative complication rates after total knee arthroplasty (TKA) in super obese (BMI > 50 kg/m(2)) patients (n = 7666) compared to non-obese patients (n = 1,212,793), obese patients (n = 291,914), morbidly obese patients (n = 169,308) and revision TKA patients (n = 28,812). Super obese patients had significantly higher rates of local and systemic complications compared to all other BMI groups as well as those undergoing revision TKA with higher rates of venous thromboembolism (VTE), infection, and medical complications. Super obesity is associated with dramatically increased rates of postoperative complications after TKA compared to non-obese, obese, and morbidly obese patients as well as those undergoing revision TKA.

Lessons learned from managing a prospective, private practice joint replacement registry: a 25-year experience.

BACKGROUND: In 1984, we developed a private practice joint replacement registry (JRR) to prospectively follow patients undergoing THA and TKA to assess clinical and radiographic outcomes, complications, and implant survival. Little has been reported in the literature regarding management of this type of database, and it is unclear whether and how the information can be useful for addressing longer-term questions. QUESTIONS/PURPOSES: We answered the following questions: (1) What is the rate of followup for THA and TKA in our JRR? (2) What factors affect followup? (3) How successful is this JRR model in capturing data and what areas of improvement are identified? And (4) what costs are associated with maintaining this JRR? METHODS: We collected clinical data on all 12,047 patients having primary THA and TKA since 1984. Clinical and radiographic data were collected at routine followup intervals and entered into a prospective database. We searched this database to assess the rate of successful followup and data collection and to compare the effect of patient variables on followup. Costs related to database management were evaluated. RESULTS: Followup was poor at every time interval after surgery, with a tendency for worsening over time. Patients with a complication and those younger than 70 years tended to followup with greater frequency. There were difficulties with data capture and substantial expenses related to managing the database. CONCLUSIONS: Our findings highlight the difficulties in managing a JRR. Followup is poor and data collection is often incomplete. Newer technologies that allow easier tracking of patients and facilitate data capture may streamline this process and control costs.

Total hip arthroplasty after failed internal fixation of proximal femoral fractures.

Between February 1987 and October 2008, we performed 102 total hip arthroplasties (THAs) after failed internal fixation of a prior hip fracture. There were 39 intertrochanteric fractures and 63 femoral neck fractures. Etiology of failure included 35 cases of osteonecrosis, 32 cases of arthritis, 25 cases of early failure of fixation, and 10 cases of nonunion. There were 12 patients who had early surgical complications related to the procedure (11.8%, 12/102). These included 5 patients who had dislocations (4.9%), 4 periprosthetic fractures (3.9%), 2 hematomas (2.0%), and 1 infection (1%). Of these 102 THAs, 50 were available for at least 2 years of follow-up (mean, 3.2 years). At a minimum 2-year follow-up, THA after failed internal fixation of hip fracture in these patients was clinically successful with an elevated risk of periprosthetic fracture and dislocation.

A comparison of two implant systems in restoration of hip geometry in arthroplasty.

BACKGROUND: Restoration of hip offset and leg length during THA is often limited by available implant geometries. The recent introduction of femoral components with a modular junction at the base of the neck (two modular junction components) has expanded the options to restore femoral offset and leg length. QUESTIONS/PURPOSES: We asked (1) whether a femoral component with two modular junctions would predict by templating more frequent restoration of preoperative offset and leg length abnormalities than one with single modular junctions; and (2) how our use of these options compared with national sales data. PATIENTS AND METHODS: We retrospectively reviewed the preoperative templating data in 100 primary THAs using single modular junction implants with only a neutral version stem and 100 THAs using two modular junction implants. We compared the frequency with which the desired leg length and offset were completely restored by preoperative templating in the two groups. RESULTS: Offset and leg lengths were restored to within 1 mm in 85% of cases with two modular junction implants and 60% of cases with single modular junction implants. An anteverted or a retroverted neck was used in 25% of cases with the two modular junction stems. The national sales data revealed femoral neck components with version were used in 28% of cases. CONCLUSIONS: The use of a femoral component with two modular junctions resulted in more frequent ability to restore femoral offset and leg length than a single modular junction. The advantage of clinical flexibility should be tempered by the potential concerns of prosthetic mechanical failure (which has been reported in another implant system with two modular junctions), increased third-body wear and corrosive debris, and increased prosthetic cost. LEVEL OF EVIDENCE: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Polyethylene exchange in a second-generation cementless acetabular component.

Some have suggested that isolated polyethylene exchange in a well-fixed Harris-Galante II acetabular component (Zimmer, Warsaw, Ind) necessitates cementing the liner or complete revision because the locking mechanism is suboptimal. We reviewed 29 hip revisions during which the polyethylene was exchanged using the native locking mechanism. Mean follow-up was 5.1 years (2-13 years). Of the 29 patients, one had a disengagement of the revision polyethylene at 2.5 years. At the time of this patient's original revision, one of the tines was fractured, but a direct exchange was performed. There were 4 other revisions (one for loosening and 3 for instability). There were no other complications attributable to the direct polyethylene exchange and no further reoperations. This series suggests that polyethylene exchange with the Harris-Galante II prosthesis can be performed safely using the native locking mechanism in the absence of fractured tines.

Single-leg-stance (flamingo) radiographs to assess pelvic instability: how much motion is normal?

BACKGROUND: Chronic pelvic instability is a relatively uncommon cause of pelvic and low-back pain. Patients present with feelings of instability and mechanical symptoms. Static radiographs are often inadequate to detect abnormal relative motion between the hemipelves consistent with chronic pelvic instability; dynamic views of the pelvis are required. We assessed the amount of physiologic motion present at the pubic symphysis in normal adult men and nulliparous and multiparous women with alternating-single-leg-stance radiographs. METHODS: Forty-five asymptomatic adult volunteers (fifteen in each group) were evaluated with a standing anteroposterior pelvic radiograph as well as with anteroposterior pelvic radiographs made with the subjects assuming both right and left single-leg stance. The subjects completed a questionnaire to determine their eligibility for participation in the study, and an examination was performed to exclude certain physical anomalies that might alter the radiographic findings. RESULTS: The mean total translation (and standard deviation) at the pubic symphysis, as measured by three blinded observers, was 1.4 +/- 1.0, 1.6 +/- 0.8, and 3.1 +/- 1.5 mm for the men, nulliparous women, and multiparous women, respectively. With the numbers available, we found no significant difference between the translation in the men and that in the nulliparous women (p = 0.63). The multiparous women had significantly more translation than did either the nulliparous women (p = 0.002) or the men (p = 0.0005). There was a significant positive association between the number of pregnancies and the total translation (p < 0.0001). CONCLUSIONS: The use of anteroposterior pelvic radiographs made with the subject alternating between right and left single-leg stance demonstrated, with high interobserver reliability, that multiparous women had a significantly different physiologic range of pubic translation as compared with men and nulliparous women. The ranges of physiologic motion at the pubic symphysis measured on the single-leg-stance radiographs in this study can be used to identify pathologic amounts of motion at this site. CLINICAL RELEVANCE: This investigation suggests that up to 5 mm of physiologic motion can occur at the pubic symphysis in asymptomatic individuals, as demonstrated by alternating-single-leg-stance radiographs.

Comprehensive morphologic evaluation of the hip in patients with symptomatic labral tear.

A torn acetabular labrum is a well-documented source of hip pain, but the mechanism of injury is debated because the relationship between the bone morphology and labral tears is poorly understood. We compared hips with and without labral abnormalities to determine the relative incidence of morphologic abnormalities. The study group consisted of patients with a labral tear confirmed by arthroscopy or arthrotomy at the time of open débridement or periacetabular osteotomy. We compared the affected hip with the contralateral, unaffected hip to ascertain signs of hip dysplasia and impingement. We observed differences in the center edge angle, acetabular depth to width index, acetabular index of elevation, femoral head extrusion, lateral and superior subluxation, Sharp's angle, peak to edge distance, and acetabular retroversion. Similar differences occurred in the subgroup analyses. Symptomatic labral tears correlated with abnormal hip morphology as reflected by radiographic measurements of dysplasia and impingement. This relationship occurred in patients with hip dysplasia and patients without obvious femoral head uncovering. Our findings suggest abnormal hip morphology may be a risk factor for labral tears.

Stacking of a dermal regeneration template for reconstruction of a soft-tissue defect after tumor excision from the palm of the hand: a case report.

Excision of tumors from the hand often leaves tissue defects with exposed tendons or neurovascular structures that require coverage. Various types of free and pedicled grafts have been described for use in these situations. We present a patient who had a tumor excision in the hand followed by wound coverage with a stacked dermal regeneration template. A 50-year-old man presented with a mass over the palm of the hand. He had an incisional biopsy procedure, the results of which suggested malignancy. He then had wide excision with planned temporary skin coverage with a dermal regeneration template. The dermal template incorporated nicely. With adequate skin coverage the palmar defect still was substantial in terms of depth. This was raised with layering or stacking of the template followed by a split-thickness skin graft. Excellent wound healing and coverage of the defect ultimately were achieved. Additionally the patient went on to obtain full range of motion. Stacking of a dermal regeneration template coupled with split-thickness skin grafting was used to fill a soft-tissue defect over the median and nerve and flexor tendons after wide tumor excision.