Multiple deep tissue cultures in primary total hip arthroplasty: prognostic value for periprosthetic infection.

BACKGROUND: The risk of infection after total hip replacement (THR) is significant, with negative impact on quality of life and high costs. Bacteria can contaminate the surgical site despite aseptic techniques; however, there is debate regarding the benefit of identifying bacteria during the primary procedure. Although taking multiple samples for culture is a well-established practice in revision arthroplasty, doing so in primary cases remains controversial. We aimed to investigate whether there is a prognostic value in the culture of samples taken during primary THR, seeking a correlation between the positivity of the cultures and subsequent prosthetic joint infection (PJI). METHODS: Deep samples (capsule, femoral and acetabular bone) were collected from 426 patients undergoing elective primary THR. Follow-up was at least 3 years. Microbiological profiles of cultures were analysed. Patient data were reviewed for the identification of risk factors presumably associated with a higher risk of PJI. RESULTS: 54 surgeries (12.6%) had positive cultures. 16 cases (3.8%) developed infection, of which 5 had a positive culture in the primary surgery. Infection rate was 9.3% in patients with positive culture and 3% in those with negative culture (p < 0.05), with an odds ratio of 3.34 (95% CI, 1.09-10.24). Patients with previous hip surgery had an infection rate of 8.5%, compared to 2.9% in patients with no previous surgery (p < 0.05). CONCLUSIONS: Routinely harvesting microbiologic samples in primary THR is not justified, as it has no consequence in clinical decision for most patients. It might be recommended in selected cases that are suspected to be at high risk for infection, especially previously operated patients (conversion arthroplasty).

Arthroscopic bullet removal from the hip joint and concurrent treatment of associated full-thickness chondral defects: A case report.

The diagnosis of a bullet inside the hip joint is a rare finding. The usual method to treat this condition has been open surgery, with its associated complications and morbidity. The arthroscopic approach has been increasingly utilized for the diagnosis and treatment of several hip conditions, and the number of indications for this technique has been steadily rising. We report the case of a 35-year-old man who suffered a gunshot wound and was operated on for abdominal perforation. He later presented with groin pain that worsened with weight-bearing on his right leg and then underwent arthroscopic removal of a bullet located inside his right hip joint. After a 2-year follow-up, the patient had an excellent clinical outcome, with no radiologic signs of arthritis. The removal of an intra-articular projectile is necessary to avoid complications such as synovitis, osteoarthritis, septic arthritis, and saturnism. The best access to the hip joint remains a topic of debate. Arthroscopy has the advantage of less soft-tissue damage and quicker recovery. The treatment of associated chondral lesions can be done with several techniques, including microfracture, autologous chondrocyte implantation, mosaicplasty, and fresh osteochondral allograft transplantation. There is no consensus as to the best course of treatment for associated chondral lesions in such cases. Hip arthroscopy can be a safe and effective technique for the removal of intra-articular bullets in the hip.

Prospective In Vivo Comparison of Damaged and Healthy-Appearing Articular Cartilage Specimens in Patients With Femoroacetabular Impingement: Comparison of T2 Mapping, Histologic Endpoints, and Arthroscopic Grading.

PURPOSE: To describe T2 mapping values in arthroscopically determined International Cartilage Repair Society (ICRS) grades in damaged and healthy-appearing articular cartilage waste specimens from arthroscopic femoroacetabular impingement (FAI) treatment. Furthermore, we sought to compare ICRS grades of the specimens with biochemical, immunohistochemistry and histologic endpoints and assess correlations with T2 mapping. METHODS: Twenty-four patients were prospectively enrolled, consecutively, between December 2011 and August 2012. Patients were included if they were aged 18 years or older and met criteria that followed the clinical indications for arthroscopy to treat FAI. Patients with prior hip trauma including fracture or dislocation or who have undergone prior hip surgery were excluded. All patients received a preoperative sagittal T2 mapping scan of the hip joint. Cartilage was graded intraoperatively using the ICRS grading system, and graded specimens were collected as cartilage waste for histologic, biochemical, and immunohistochemistry analysis. RESULTS: Forty-four cartilage specimens (22 healthy-appearing, 22 damaged) were analyzed. Median T2 values were significantly higher among damaged specimens (55.7 ± 14.9 ms) than healthy-appearing specimens (49.3 ± 12.3 ms; P = .043), which was most exaggerated among mild (grade 1 or 2) defects where the damaged specimens (58.1 ± 16.4 ms) were significantly higher than their paired healthy-appearing specimens (48.7 ± 15.4 ms; P = .026). Severely damaged specimens (grade 3 or 4) had significantly lower cumulative H&E than their paired healthy-appearing counterparts (P = .02) but was not statistically significant among damaged specimens with mild (grade 1 or 2) defects (P = .198). Among healthy-appearing specimens, median T2 and the percentage of collagen fibers oriented parallel were significantly correlated (rho = 0.425, P = .048). CONCLUSIONS: This study outlines the potential for T2 mapping to identify early cartilage degeneration in patients undergoing arthroscopy to treat FAI. Findings in ICRS grade 1 and 2 degeneration corresponded to an increase in T2 values. Further biochemical evaluation revealed a significant difference between healthy-appearing cartilage and late degeneration in cumulative H&E as well as significantly lower percentage of collagen fibers oriented parallel and a higher percentage of collagen fibers oriented randomly when considering all grades of cartilage damage. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Comparison of T2 Values in the Lateral and Medial Portions of the Weight-Bearing Cartilage of the Hip for Patients With Symptomatic Femoroacetabular Impingement and Asymptomatic Volunteers.

PURPOSE: To develop a simplified method to define a clinically relevant subregion in the course of arthroscopic treatment of femoroacetabular impingement (FAI) using T2 mapping in patients and asymptomatic volunteers. Additionally, we sought to compare the lateral and medial subregion values in asymptomatic volunteers and in patients presenting with FAI. Finally, we wanted to investigate possible associations between patients' T2 mapping values and demographic variables-i.e., alpha angle, age, sex, and body mass index (BMI). METHODS: Twenty-five asymptomatic volunteers and 23 consecutive symptomatic patients with FAI (cam or mixed type) were prospectively enrolled and evaluated with a sagittal T2 mapping sequence. The weight-bearing region of the acetabular and femoral cartilage was manually segmented and divided into medial and lateral subregions. Median T2 values were determined, and patient characteristics were assessed as potential predictors of T2 values. RESULTS: T2 values in the lateral portion of the acetabulum were lower than in the medial portion for both asymptomatic volunteers (43 v 53 ms; P < .001) and patients with FAI (42 v 49 ms; P = .016). The medial acetabulum (MA) of asymptomatic volunteers had higher T2 values than those of the FAI group (53 v 49 ms; P = .040). The lateral-minus-medial difference was significantly larger among asymptomatic volunteers than in patients with FAI (P = .047). Patients with FAI had higher alpha angles than those of the asymptomatic volunteers, but no other associations with patient characteristics were observed. CONCLUSIONS: This study's findings suggest that there are differences in cartilage T2 mapping values between medial and lateral weight-bearing aspects of the hip and may expand the application and usefulness of biochemical magnetic resonance imaging (MRI) techniques, specifically T2 mapping, in the diagnosis of hip cartilage damage with the evaluation of clinically relevant subregions. When comparing asymptomatic volunteers and patients with FAI presenting with cam or mixed type deformity, we observed a significant contrast between the T2 mapping values of the lateral and medial portions of the weight-bearing zone of the acetabular cartilage, whereas such contrast was not observed when zone 3 was analyzed as a whole. LEVEL OF EVIDENCE: Level III, development of diagnostic criteria on the basis of consecutive patients with a universally applied reference gold standard.

Tensile properties of the human acetabular labrum and hip labral reconstruction grafts.

BACKGROUND: In cases where the acetabular labrum is severely damaged and irreparable, labral reconstructions are becoming an increasingly preferred means of preserving the fluid seal effect of the labrum. However, the graft that most closely replicates the biomechanical properties of the native labrum remains undetermined. PURPOSE: To characterize the tensile properties and geometry of the labrum, as well as iliotibial band, semitendinosus, gracilis, and anterior tibialis grafts. STUDY DESIGN: Controlled laboratory study. METHODS: Five graft groups--(1) acetabular labrum, (2) iliotibial band, (3) semitendinosus, (4) gracilis, and (5) anterior tibialis--with 8 specimens per group were tested. Grafts were tested using a materials testing system in response to a stepwise sinusoidal cyclic loading protocol. Uniaxial tensile loads were initially applied from 20 to 50 N for 100 cycles at 0.5 Hz, followed by incremental increases of 50 N in the upper force every 100 cycles until failure or successful completion of 100 cycles at 300 N. This protocol was designed to be representative of progressive loading experienced during rehabilitation. Cyclic displacement was recorded after 100 (50 N), 200 (100 N), 300 (150 N), 400 (200 N), 500 (250 N), and 600 (300 N) cycles. RESULTS: The mean elongation (95% CI) after 100 cycles from 20 to 50 N was similar for all groups: acetabular labrum, 0.68 mm (0.57-0.78 mm); iliotibial band, 0.68 mm (0.47-0.89 mm); semitendinosus, 0.68 mm (0.51-0.84 mm); gracilis, 0.62 mm (0.46-0.79 mm); and anterior tibialis, 0.66 mm (0.58-0.73 mm). After 100 cycles from 20 to 300 N (600 cycles total), the mean elongation of the labrum was 4.53 mm (3.71-5.35 mm), and the mean elongations of the iliotibial band, semitendinosus, gracilis, and anterior tibialis were 4.65 mm (3.23-6.07 mm), 4.41 mm (3.45-5.36 mm), 5.12 mm (3.09-7.16 mm), and 5.33 mm (4.40-6.25 mm), respectively. CONCLUSION: All tested grafts and the acetabular labrum exhibited similar cyclic elongation behavior in response to simulated physiologic forces. In addition, differences in variability in both elongation and geometry existed for all graft types. CLINICAL RELEVANCE: All tested grafts can be considered viable acetabular labrum reconstruction graft options.

Arthroscopy provides symptom relief and good functional outcomes in patients with hip synovial chondromatosis.

UNLABELLED: The purpose of this study was to evaluate clinical presentation, associated pathology and clinical outcomes after arthroscopic treatment of hip synovial chondromatosis (SC). A prospective data registry was queried for patients with SC diagnosis from 2005 to 2012. Surgical indications were intra-articular pain after failure of conservative treatment, labral pathology, chondral damage or loose bodies. All patients had femoroacetabular impingement based on radiographic findings. Patient-centered outcomes were collected before and after surgery. Standard hip arthroscopy techniques were used to address associated pathology. Twenty-three patients met the inclusion criteria. Eleven were males. Mean age was 43.7 years. Mean center-edge angle was 33.7 and alpha angle 73. Radiographs were diagnostic in five patients (23.8%). Magnetic resonance imaging identified loose bodies in 14 (66%). Most patients had an uncountable amount of loose bodies in the central and peripheral compartments. The most common associated pathology was a labral tear (100%) and acetabular cartilage injury (85%). All patients had improvement in range of motion. The average Modified Harris Hip score improved from 62 (pre-op) to 84.8 (post-op). Short-Form 12-PCS improved from 41 to 53. Western Ontario and McMaster Osteoarthritis Index improved from 27.1 to 7.2. Median overall satisfaction was 9.5 (out of 10). Hip arthroscopy with thorough removal of loose bodies and subtotal synovectomy, coupled with an aggressive and early rehabilitation program, was effective in ameliorating symptoms associated with from hip SC, yielding high levels of patient satisfaction and functional outcomes, in a 2.5 year follow-up time. LEVEL OF EVIDENCE: IV (case series).

Structural properties of the intact proximal hamstring origin and evaluation of varying avulsion repair techniques: an in vitro biomechanical analysis.

BACKGROUND: Although surgical repair has been reported to provide improved outcomes compared with nonoperative treatment in the management of complete proximal hamstring origin avulsions, no intact or avulsion repair biomechanical data exist to support various repair strategies or guide postoperative rehabilitation. PURPOSE: To compare failure load among 4 proximal hamstring tendon conditions: (1) intact, (2) repair with 2 small anchors (2S), (3) repair with 2 large anchors (2L), and (4) repair with 5 small anchors (5S). STUDY DESIGN: Controlled laboratory study. METHODS: Twenty-four human cadaveric hemipelvises were randomly allocated to 1 of the 4 testing groups. Intact and repaired specimens were subjected to cyclic loading at 1 Hz between 25 N and a progressively increasing maximum load that was incremented by 200 N every 50 cycles, beginning at 200 N and increasing to 1600 N. Displacement, maximum load, stiffness, number of cycles to failure, and mode of failure during cyclic loading were recorded and analyzed. RESULTS: The intact proximal hamstring tendons failed at the highest cyclic force of all tested groups, yet no significant differences existed between the intact (1405 ± 157 N) and 5S repair (1164 ± 294 N) conditions. Both the 2S and the 2L repair groups failed at a level significantly lower than the intact hamstring (474 ± 145 N [P < .001] and 543 ± 245 N [P < .001], respectively). The maximum load attained by the 5S repairs was significantly greater than the loads attained by the 2S (P = .005) and 2L (P = .013) repairs. CONCLUSION: Repairs using 5 small anchors were similar to the intact tendon and were significantly stronger than repairs using only 2 large or 2 small anchors in the repair of complete avulsions of the proximal hamstring tendons. Additionally, no significant differences in strength were observed when only anchor size differed. CLINICAL RELEVANCE: This finding supports the clinical investigation of postoperative range of motion rehabilitation protocols that permit full flexion and extension of the hip and knee when a 5-anchor repair construct is used.

Patient-centered outcomes after hip arthroscopy for femoroacetabular impingement and labral tears are not different in patients with normal, high, or low femoral version.

PURPOSE: The purpose of this study was to determine whether outcomes after hip arthroscopy were different based on femoral version. METHODS: The inclusion criteria were diagnosis of femoroacetabular impingement (FAI) based on clinical examination and/or imaging findings and preoperative measurement of femoral version by magnetic resonance imaging. For this study, the definition of FAI was a positive impingement sign, a positive flexion-abduction-external rotation examination finding, or radiographic signs of impingement. A query of a prospective data registry identified 180 patients who matched the inclusion and exclusion criteria. Group 1 had version of less than 5° (n = 48), group 2 had version of 5° to 15° (n = 84), and group 3 had version greater than 15° (n = 48). The mean age of the patients was 35 years (range, 18 to 61 years). RESULTS: On radiographic examination, the mean alpha angle for all patients' injured hips was 63° (range, 42° to 88°). The mean center-edge angle was 30° (range, 20° to 43°), and mean femoral version was 9.9° (range, -16° to 29°). There was no significant difference in age, alpha angle, or center-edge angle among the 3 version groups. A significant difference in psoas release procedures (psoas impingement) was seen with increasing femoral version. The mean follow-up period was 30 months (range, 18 to 47 months). Patient-reported functional outcomes were not statistically different among the groups. CONCLUSIONS: Patient-reported functional outcomes after hip arthroscopy for labral tears and FAI were not different based on femoral version in this population. Although some differences were observed regarding intraoperative findings, these also did not result in differences in patient outcomes reported at a mean follow-up of 2 years. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

A qualitative and quantitative analysis of the attachment sites of the proximal hamstrings.

PURPOSE: Proximal hamstring tears represent a challenge. Surgical repair of such tears has been reported utilizing both open and endoscopic techniques. It was hypothesized that the proximal attachments of the hamstring muscle group could be reproducibly and consistently measured from pertinent bony anatomical reference landmarks. METHODS: Fourteen fresh-frozen, human cadaveric specimens were dissected, and measurements were taken regarding the proximal attachments of the hamstring muscle group in reference to bony landmarks. A highly precise coordinate measuring device was used for three-dimensional measurements of tendon footprints and bony landmarks, and relevant distances between structures were calculated. RESULTS: The semitendinosus and long head of the biceps femoris shared a proximal origin (conjoined tendon), having an oval footprint with an average area of 567.0 mm(2) [95 % CI 481.0-652.9]. The semimembranosus (SM) footprint was crescent-shaped and located anterolateral to the conjoined tendon, with an average area of 412.4 mm(2) [95 % CI 371.0-453.8]. The SM footprint had an accessory tendinous extension that extended anteromedially forming a distinct footprint. A consistent bony landmark was found at the medial ischial margin, 14.6 mm [95 % CI 12.7-16.5] from the centre of the conjoined tendon footprint, which coincided with the distal insertion of the sacrotuberous ligament. CONCLUSION: The conjoined tendon was the largest attachment of the proximal hamstring group. Two other distinct attachment footprints were identified as the SM footprint and the accessory tendinous extension. The sacrotuberous ligament insertion served as a bony landmark. The anatomical data established in this study may aid in better restoring the anatomy during repair of proximal hamstring tears.

Hip capsulolabral spacer placement for the treatment of severe capsulolabral adhesions after hip arthroscopy.

Recently, there has been a rapid increase in the number of hip arthroscopies performed. The increase in the number of primary surgeries has been associated with a similar increase in the number of revision procedures. The most frequent indications for revision hip arthroscopy are residual bony deformity (impingement), persistent labral pathology, and intra-articular adhesions. Our current understanding of capsulolabral adhesions is limited. Although adhesions between the capsule and labrum are common after hip arthroscopy, generally, they are mild and asymptomatic. However, in severe cases they may cause persistent synovitis and pain, and they may tether the labrum away from the femoral head, causing loss of the suction-seal effect. Such patients present with nonspecific symptoms such as persistent pain, giving way, catching, and pain in hip flexion. Magnetic resonance imaging can aid in the diagnosis by showing the absence of liquid in the capsulolabral recess, although the definitive diagnosis is based on dynamic arthroscopic evaluation. We present our approach to the lysis of capsulolabral adhesions with preservation of labral tissue and describe a technique that uses an iliotibial band allograft to prevent recurrence of such adhesions by maintaining space between the capsule and labrum.

Subregional Anatomical Distribution of T2 Values of Articular Cartilage in Asymptomatic Hips.

OBJECTIVE: A standardized definition of normative T2 values across the articular surface of the hip must be defined in order to fully understand T2 values for detecting early degeneration. Therefore, in this article, we seek to lay foundational methodology for reproducible quantitative evaluation of hip cartilage damage using T2 mapping to determine the normative T2 values in asymptomatic individuals. DESIGN: Nineteen prospectively enrolled asymptomatic volunteers (age 18-35 years, males 10, females 9, alpha angle 49.3º ± 7.2º) were evaluated with a sagittal T2 mapping sequence at 3.0 T magnetic resonance imaging. Acetabular and femoral cartilage was manually segmented directly on the second echo of the T2 mapping sequence by 3 raters, twice. Segmentations were divided into 12 subregions modified from the geographic zone method. Median T2 values within each subregion were compiled for further analysis and interrater and intrarater reliability was assessed. RESULTS: In the femur, the posterior-superior subregion was significantly higher (P ≤ 0.05) than those in the posterior-inferior and anterior-inferior subregions. In the acetabulum, the anterior-inferior subregion was significantly higher (P ≤ 0.001) than in the anterior-superior, middle, and posterior-inferior subregions. T2 values of the posterior-superior subregion were significantly higher (P ≤ 0.05) than the anterior-superior, middle, and posterior-inferior subregions. Interrater agreement was generally fair to good.