The Effect of Resection Size in the Treatment of Cam-Type Femoroacetabular Impingement in the Typical Patient With Hip Arthroscopy: A Biomechanical Analysis.

BACKGROUND: Arthroscopic osteochondroplasty may improve range of motion and relieve pain in patients with symptomatic hip impingement. Femoral neck fracture is a risk of this procedure because of the weakening of the proximal femur. To our knowledge, there are no biomechanical studies in young human cadaveric bone evaluating the effect of osteochondroplasty on femoral neck strength. PURPOSE/HYPOTHESIS: The purpose was to evaluate loads to fracture in young human cadavers after resection depths of 25% and 40% at the head-neck junction. We hypothesized that both depths will maintain ultimate loads to failure above previously published loads, as well as above physiologic weightbearing loads. STUDY DESIGN: Descriptive laboratory study. METHODS: Cadaveric proximal femoral specimens (6 matched pairs, under the age of 47 years) were divided into 2 groups: 25% or 40% of the diameter at the head-neck junction was resected. The length of the resection was 2 cm and the width of the resection was determined by the length of the anterolateral quadrant at the head-neck junction in all cases. A compressive load was applied directly to the femoral head. Peak load, stiffness, and energy to fracture were compared between groups. RESULTS: The average peak load to fracture after 25% resection (7347 N) was significantly higher than after the 40% resection (5892 N) (P = .010). The average energy to fracture was also significantly higher in the 25% resection group (30.2 J vs 19.2 J; P = .007). The average stiffness was higher in the 25% group, although not statistically significant (P = .737). CONCLUSION: Resection depths of 25% and 40% at the anterolateral quadrant of the femoral head-neck junction may be safe at previously described functional loads such as standing and walking in the age range more typically seen in patients undergoing hip arthroscopy. Loads to fracture were significantly higher than previously reported using older cadaveric specimens. CLINICAL RELEVANCE: Currently, most surgeons limit weightbearing after femoral osteochondroplasty in part because of risk of femoral neck fracture. Given the higher observed loads to fracture, young patients could possibly bear weight sooner after surgery, although postoperative protocols should be individualized based on patient age, weight, bone density, amount of bone resected, concomitant procedures, and potential compliance with activity restrictions.

Arthroscopic Treatment of Femoroacetabular Impingement in Patients over 60 Years Old: Preliminary Report of a Pilot Study.

The objective was to evaluate short-term outcomes of patients of more than 60 years old, who underwent arthroscopic treatment for femoroacetabular impingement (FAI). The study design was a nonrandomized controlled clinical trial; this was a prospective study in 15 patients (15 hips) over 60 years old. Inclusion criteria were symptomatic FAI, no prior surgeries of the affected hip, and osteoarthritis Tonnis classification grade I or II. Exclusion criteria were multiple or large (≥5 mm) chondral defects or subchondral bone cysts in the acetabulum or the femoral head seen on magnetic resonance imaging (MRI). Radiographs and MRI arthrograms were used for the imaging assessment in all cases. Procedures performed arthroscopically included labrum resection, acetabuloplasty, and femoral osteoplasty in all cases. The Harris Hip Score was applied preoperatively and 2 years postoperatively. At 2 years postoperatively, the average increase in the Harris Hip Score was 21 points (mainly pain reduction) from a mean preoperative score of 66 points to a mean postoperative score of 87 points; this difference was significant (P < 0.05). Three cases (20%) had poor outcomes and required a total hip replacement during the first year after the surgery. Poor results were associated with Tonnis grade II osteoarthritis and Outerbridge grade III or IV chondral defects. Arthroscopic treatment of FAI of patients over 60 years old showed a significant Harris Hip Score increase as a result of excellent and good short-term clinical results in most of the patients of our study. Nevertheless, despite strict selection criteria for very well-selected patients, we observed an early failure rate of up to 20%.

Anterior and Posterior Femoral Head-Neck Offset Ratio in the Cam Impingement.

PURPOSE: The purpose of this study was to determine if the anterior-posterior offset ratio is altered in patients with symptomatic cam impingement. STUDY DESIGN: Preoperative radiographs of 15 symptomatic patients with isolated cam-type impingement diagnosed by physical examination and magnetic resonance imaging arthrogram (MRIA) and confirmed by hip arthroscopy findings were assessed. Fifteen asymptomatic volunteers made up the control group. The anterior offset (AO), posterior offset (PO), and AO/PO ratio were calculated. RESULTS: The mean ± SD AO/PO ratio was 0.56 ± 0.1 for the symptomatic group and 0.9 ± 0.2 for the asymptomatic group. This difference was statistically significant. Intra- and interobserver correlation factor for calculating the AO/PO ratio was 0.8 and 0.5, respectively, and differences were not statistically different. CONCLUSIONS: The AO/PO ratio in this study was a useful radiological parameter for the assessment of patients with a cam-type impingement.

Efficacy of Osseous Abnormalities Correction with Arthroscopic Surgery in Femoroacetabular Impingement.

UNLABELLED: Femoroacetabular impingement (FAI) is a clinical syndrome characterized by subtle abnormal morphology of the proximal femur and/or the acetabulum that leads to abnormal contact between the femoral neck and the acetabular rim during the hip range of motion. Traditionally, FAI has been managed safely and effectively with surgical hip dislocation; less invasive arthroscopic techniques are now being used to an increasing extent, trying to emulate the results of the open technique. The purpose of this study was to evaluate the radiographic results of arthroscopic acetabular rim trimming and femoral osteochondroplasty in FAI. This was a retrospective analysis of preoperative and postoperative plain radiographs of 80 patients treated for FAI with arthroscopic surgery between April 2007 and December 2008. We evaluated 2 parameters: the Wiberg angle (center-edge angle) (normal, 25°-35°), and the anterior/posterior relation of femoral head-neck offset (normal, 0.8-1). Of 80 hips, 10 (12.5%) were pincer-type impingement, 17 (21.25%) were cam type, and 53 (66.25%) were mixed type. The preoperative Wiberg average was 39° (range, 25°-51°), and the postoperative Wiberg average was 32° (range, 25°-42°). The preoperative anterior/posterior femoral offset relation average was 0.42 (range, -0.38 to 1), and the postoperative anterior/posterior femoral offset relation average was 0.94 (range, 0.61-1.2). Our results show that it is possible to obtain an anatomical correction of the osseous abnormalities with arthroscopic surgery in FAI. LEVEL OF EVIDENCE: level III.

Porous tantalum and poly-epsilon-caprolactone biocomposites for osteochondral defect repair: preliminary studies in rabbits.

Currently, various techniques are in use for the repair of osteochondral defects, none of them being truly satisfactory and they are often two step procedures. Comorbidity due to cancellous bone harvest from the iliac crest further complicates the procedure. Our previous in vitro studies suggest that porous tantalum (TM) or poly-epsilon-caprolactone scaffolds (PCL) in combination with periosteal grafts could be used for osteochondral defect repair. In this in vivo study, cylindrical osteochondral defects were created on the medial and lateral condyles of 10 rabbits and filled with TM/periosteum or PCL/periosteum biosynthetic composites (n = 8 each). The regenerated osteochondral tissue was then analyzed histologically, and evaluated in an independent and blinded manner by five different observers using a 30-point histological score. The overall histological score for PCL/periosteum was significantly better than for TM/periosteum. However, most of the regenerates were well integrated with the surrounding bone (PCL/periosteum, n = 6.4; TM/periosteum, n = 7) along with partial restoration of the tidemark (PCL/periosteum, n = 4.4; TM/periosteum, n = 5.6). A cover of hyaline-like morphology was found after PCL/periosteum treatment (n = 4.8), yet the cartilage yields were inconsistent. In conclusion, the applied TM and PCL scaffolds promoted excellent subchondral bone regeneration. Neo-cartilage formation from periosteum supported by a scaffold was inconsistent. This is the first study to show in vivo results of both PCL and TM scaffolds for a novel approach to osteochondral defect repair.

Early complications of operatively treated proximal humeral fractures.

Minimal information exists regarding early complications after operatively treated proximal humeral fractures. Of the 82 shoulders that had osteosynthesis, 42 had a (nonmedical) complication, with 21 requiring further surgery. Of 42 shoulders with complications, 12 were related to incomplete reduction, 16 had loss of anatomic fracture fixation, 9 had delayed healing, 3 had an infection, 1 had rotator cuff failure, and 1 had loose bodies. Fixed-angle plates had lower rates of initial malpositioning and resultant malunion. Of the 22 shoulders requiring hemiarthroplasty, 14 had an early complication. Of these, 7 had complications relating to implant insertion or tuberosity malreduction at the index operation and 7 had problems with tuberosity healing. The rate of complications after operative treatment of proximal humeral fractures is high. All efforts at fracture fragment fixation with osteosynthesis and hemiarthroplasty should be directed at obtaining anatomic fracture fixation that resists displacement.

Surgical treatment of femoroacetabular impingement: evaluation of the effect of the size of the resection. Surgical technique.

BACKGROUND: In patients with symptomatic hip impingement, surgical resection of the femoral head-neck junction may improve the range of motion and relieve pain. A risk of this procedure is fracture. We evaluated the amount of resection of the anterolateral aspect of the femoral head-neck junction that can be done safely. METHODS: Cadaveric proximal femoral specimens (fifteen matched pairs) were divided into three groups: 10%, 30%, or 50% of the diameter of one femoral neck was removed, and the contralateral femoral neck was left intact to serve as the control. A compressive load was applied directly to the femoral head. Peak load, stiffness, and energy to fracture were compared among the groups. RESULTS: The energy to fracture differed significantly (p = 0.0015) among the 10%, 30%, and 50% resection groups. The peak load after the 50% resection was significantly less (p = 0.0025) than that after the 10% or 30% resection. With the numbers available, there was no significant difference in peak load between the 10% and 30% resections. CONCLUSIONS: Resection of up to 30% of the anterolateral quadrant of the head-neck junction did not significantly alter the load-bearing capacity of the proximal part of the femur. However, a 30% resection significantly decreased the amount of energy required to produce a fracture. Thirty percent should be considered to be the greatest feasible amount of resection because of the change in the pattern of the femoral head-neck response to axial loads that we observed.

Development of a biologic prosthetic composite for cartilage repair.

At present there is no satisfactory treatment for deep osteochondral defects. Here we report the development of a biologic prosthetic composite containing periosteum from 2-month-old rabbits and a porous tantalum scaffold. When cultured under chondrogenic conditions, the composites form a robust hyaline-like cartilage outgrowth that is attached to the porous scaffold by fibrous tissue ingrowth. The mechanical properties of these composites are similar to those of normal osteochondral plugs after only 6 weeks in culture. Thus, porous tantalum scaffolds are compatible with the chondrogenic capacity of periosteum. We hypothesize that these periosteum-porous tantalum composites will be useful for the repair of major osteochondral defects. However, in vivo experiments using biological resurfacing of large osteochondral defects with a porous tantalum scaffold and autologous periosteal graft in animal models are necessary to further explore this possibility. The implications of a successful method for cartilage regeneration would be great in terms of the number of patients affected and the quality of life for each of those patients.

Surgical treatment of femoroacetabular impingement: evaluation of the effect of the size of the resection.

BACKGROUND: In patients with symptomatic hip impingement, surgical resection of the femoral head-neck junction may improve the range of motion and relieve pain. A risk of this procedure is fracture. We evaluated the amount of resection of the anterolateral aspect of the femoral head-neck junction that can be done safely. METHODS: Cadaveric proximal femoral specimens (fifteen matched pairs) were divided into three groups: 10%, 30%, or 50% of the diameter of one femoral neck was removed, and the contralateral femoral neck was left intact to serve as the control. A compressive load was applied directly to the femoral head. Peak load, stiffness, and energy to fracture were compared among the groups. RESULTS: The energy to fracture differed significantly (p = 0.0015) among the 10%, 30%, and 50% resection groups. The peak load after the 50% resection was significantly less (p = 0.0025) than that after the 10% or 30% resection. With the numbers available, there was no significant difference in peak load between the 10% and 30% resections. CONCLUSIONS: Resection of up to 30% of the anterolateral quadrant of the head-neck junction did not significantly alter the load-bearing capacity of the proximal part of the femur. However, a 30% resection significantly decreased the amount of energy required to produce a fracture. Thirty percent should be considered to be the greatest feasible amount of resection because of the change in the pattern of the femoral head-neck response to axial loads that we observed.