Iliopsoas Impingement After Direct Anterior Approach Total Hip Arthroplasty: Epidemiology, Risk Factors, and Treatment Options.

BACKGROUND: The objective of this study is to evaluate the incidence, natural history, response to treatment, and risk factors for anterior iliopsoas impingement (AIPI) after direct anterior approach (DAA) total hip arthroplasty (THA). METHODS: Between January 1, 2009 and January 4, 2014, 600 patients (655 hips) who underwent primary DAA THA were retrospectively reviewed. AIPI incidence was calculated. Natural history and response to a stepwise treatment approach was assessed. Radiographic anterior acetabular component overhang was measured. Asymptomatic controls were used to identify risk factors for the development of AIPI. RESULTS: In total, 518 patients (559 hips) met the inclusion criteria. The incidence of AIPI was 32/559 (5.7%). Symptom resolution occurred in 22/32 (68.8%) patients at final follow-up. Nonoperative management was successful in 15/32 (46.9%) patients. Operative intervention resulted in symptom resolution in 5/8 (62.5%) patients. On univariate analysis, female gender (odds ratio [OR] 2.79), acetabular component to native femoral head diameter ratio above 1.1 (OR 3.85), and any measurable overhang (OR 7.07) significantly raised the risk of AIPI, while increasing native femoral head diameter was protective for AIPI (OR 0.83). CONCLUSION: AIPI is a cause of groin pain after DAA THA, which often improves with conservative measures. Significant predisposing factors for AIPI include female gender, small native femoral head diameter, increased acetabular component to femoral head diameter ratio, and most notably, any measurable acetabular component overhang. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Closed incision negative pressure therapy decreases complications after periprosthetic fracture surgery around the hip and knee.

INTRODUCTION: Periprosthetic fractures (PPFXs) are becoming increasingly common following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Patients sustaining PPFXs face considerable perioperative morbidity, with relatively increased rates of surgical site infection. We sought to evaluate the efficacy of closed-incision negative-pressure wound therapy (ciNPT) in decreasing perioperative wound complications following lower extremity periprosthetic fracture surgery. METHODS: We performed a retrospective review of 69 consecutive patients who underwent surgery to address lower extremity periprosthetic fractures around hip or knee implants performed over a 6.5-year period. The population was divided into two groups based on the surgical dressing used at the conclusion of the procedure: (1) a sterile, antimicrobial hydrofiber dressing, or (2) ciNPT. There were no baseline demographic differences between the two groups. Rates of wound complications, surgical site infection, and reoperation related to the surgical site were compared between groups. Continuous variables were analyzed using a student's t-test, and categorical variables using either chi-square or fisher's exact test. RESULTS: Patients treated with ciNPT developed fewer wound complications (4% vs. 35%; p=0.002), fewer deep infections (0% vs. 25%; p=0.004), and underwent fewer reoperations related to the surgical site (4% vs. 25%; p=0.021) compared to patients treated with standard of care. CONCLUSIONS: Our findings suggest that ciNPT may reduce wound complications, SSIs, and reoperations in patients undergoing lower extremity periprosthetic fracture surgery. This is the first study to investigate ciNPT as a treatment for periprosthetic fracture surgery, and has the potential to change the postoperative management of these patients.

Hemispherical and minimally invasive total hip reamers: a biomechanical analysis of use and design.

BACKGROUND: The purpose of this study was to determine the accuracy of used and new reamer systems for both hemispherical and minimally invasive (MIS) acetabular reamers. METHODS: New and used hemispherical and MIS acetabular reamers were tested on a computer numerical control machine to ream holes in special machinable wax blocks. Each reamer was tested 3 times in sizes 48 mm through 55 mm. RESULTS: The used reamers significantly underreamed by an average of 1.33 vs 0.28 mm compared to new reamers. Hemispherical reamers underreamed significantly more than MIS reamers, with a mean difference of 0.99 vs 0.63 mm, respectively. Used hemispherical reamers showed an average ream undersize of 1.61 vs 0.37 mm, compared to new hemispherical reamers. Used MIS reamers showed an average ream undersize of 1.06 vs 0.20 mm for the new MIS reamers. CONCLUSIONS: For a manufacturer-specified reamer size, both hemispherical and MIS reamers underream. Newer reamers cut truer to expected values than used ones. MIS reamers performed more accurately than hemispherical reamers. Used acetabular reamer systems may negatively affect the sizing of prepared acetabular beds; therefore, awareness of this potential inaccuracy should be considered when performing total hip arthroplasty.

Effects of lumbar disk herniation on the careers of professional baseball players.

Outcomes after lumbar disk herniation in baseball athletes are currently unknown. It has been postulated that the repetitive torque-producing motions of a baseball player may have negative implications after a disk injury. Sixty-nine lumbar disk herniations (40 treated operatively, 29 nonoperatively) in 64 professional baseball players were identified, and important outcome measures including successful return to play, time to recovery, career longevity, and performance based on vital statistics to each position were documented. Ninety-seven percent of baseball athletes successfully returned to play at an average of 6.6 months after diagnosis. Athletes treated operatively required significantly more time to return to play than those managed nonoperatively (8.7 vs 3.6 months, respectively; P<.0001).

Outcomes of cervical and lumbar disk herniations in Major League Baseball pitchers.

The effects of disk herniations on the career and performance outcomes of Major League Baseball (MLB) pitchers are unknown. The purpose of this study is to determine the outcomes after a cervical or lumbar disk herniation for MLB pitchers. Forty MLB pitchers from 1984 to 2009 with a cervical disk herniation or lumbar disk herniation were identified using a previously established protocol. Cervical disk herniation was identified in 11 pitchers, 8 of which were treated operatively. The majority of pitchers with cervical disk herniation (8/11) returned to play at an average of 11.6 months. Lumbar disk herniation was identified in 29 pitchers, 20 of which were treated operatively. All pitchers with lumbar disk herniation (29/29) returned to play at an average of 7.3 months after diagnosis.

Nanocomposite therapy as a more efficacious and less inflammatory alternative to bone morphogenetic protein-2 in a rodent arthrodesis model.

The use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in spine fusion has led to concerns regarding a potential accompanying inflammatory response. This study evaluates a combination therapy (TrioMatrix®; Pioneer Surgical, Inc., Marquette, MI) comprised of a demineralized bone matrix (DBM), hydroxyapatite, and a nanofiber-based collagen scaffold in a rodent spine fusion model. Thirty-six athymic rats that underwent a posterolateral intertransverse spinal fusion were randomly assigned to 1 of 5 treatment groups: absorbable collagen sponge alone (ACS, negative control), 10 µg rhBMP-2 on ACS (positive control), TrioMatrix®, Grafton® (Osteotech, Inc., Eatontown, NJ), and DBX® (Synthes, Inc., West Chester, PA). Both TrioMatrix® and rhBMP-2-treated animals demonstrated 100% fusion rates as graded by manual palpation scores 8 weeks after implantation. This rate was significantly greater than those of the ACS, Grafton®, and DBX® groups. Notably, the use of TrioMatrix® as evaluated by microCT quantification led to a greater fusion mass volume when compared to all other groups, including the rhBMP-2 group. T2-weighted axial MRI images of the fusion bed demonstrated a significant host response associated with a large fluid collection with the use of rhBMP-2; this response was significantly reduced with the use of TrioMatrix®. Our results therefore demonstrate that a nanocomposite therapy represents a promising, cost-effective bone graft substitute that could be useful in spine fusions where BMP-2 is contraindicated.

The Professional Athlete Spine Initiative: outcomes after lumbar disc herniation in 342 elite professional athletes.

BACKGROUND CONTEXT: Although clinical outcomes after lumbar disc herniations (LDHs) in the general population have been well studied, those in elite professional athletes have not. Because these athletes have different measures of success, studies on long-term outcomes in this patient population are necessary. PURPOSE: This study seeks to define the outcomes after an LDH in a large cohort of professional athletes of American football, baseball, hockey, and basketball. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: A total of 342 professional athletes from four major North American sports from 1972 to 2008 diagnosed with an LDH were identified via a previously published protocol. Two hundred twenty-six players underwent lumbar discectomy, and 116 athletes were treated nonoperatively. Only those players who had at least 2 years of follow-up were included. OUTCOME MEASURES: Functional outcome measures as defined by successful return-to-play (RTP), career games, and years played for each player cohort were recorded both before and after treatment. Conversion factors based on games/regular season and expected career length (based on individual sport) were used to standardize the outcomes across each sport. METHODS: Using Statistical Analysis Software v. 9.1, outcome measures were compared in each cohort both before and after treatment using linear and mixed regression analyses and Cox proportional hazards models. A Kaplan-Meier survivorship curve was calculated for career length after injury. Statistical significance was defined as p<.05. RESULTS: After the diagnosis of an LDH, professional athletes successfully returned to sport 82% of the time, with an average career length of 3.4 years. Of the 226 patients who underwent surgical treatment, 184 successfully returned to play (81%), on average, for 3.3 years after surgery. Survivorship analysis demonstrated that 62.3% of players were expected to remain active 2 years after diagnosis. There were no statistically significant differences in outcome in the surgical and nonoperative cohorts. Age at diagnosis was a negative predictor of career length after injury, whereas games played before injury had a positive effect on outcome after injury. Major League Baseball (MLB) players demonstrated a significantly higher RTP rate than those of other sports, and conversely, National Football League (NFL) athletes had a lower RTP rate than players of other sports (p<.05). However, the greatest positive treatment effect from surgery for LDH was seen in NFL players, whereas for MLB athletes, a lumbar discectomy led to a shorter career compared with the nonoperative cohort (p<.05). CONCLUSIONS: Professional athletes diagnosed with an LDH successfully returned to play at a high rate with productive careers after injury. Whereas older athletes have a shorter career length after diagnosis of LDH, experienced players (high number of games played) demonstrate more games played after treatment than inexperienced athletes. Notably, surgical treatment in baseball players led to significantly shorter careers, whereas for NFL athletes, posttreatment careers were longer than those of the corresponding nonoperative cohort. The explanation for this is likely multifactorial, including the age at diagnosis, respective contractual obligations, and different physical demands imposed by each individual professional sport.