A Coxoperitoneal Shunt as Salvage for a Recurrent Giant Seroma of the Hip After Periprosthetic Joint Infection: A Case Report.

CASE: A giant seroma developed in the hip of a 44-year-old man after resection arthroplasty performed for recurrent periprosthetic joint infection (PJI). The seroma persisted despite joint reconstruction but was ultimately treated successfully by internal drainage through a coxoperitoneal shunt. CONCLUSION: Resection arthroplasty of the hip is considered a salvage procedure for failed implant retention in the situation of persistent PJI. Nevertheless, functional results are poor and further soft-tissue complications may occur. A giant seroma of the hip may be drained into the peritoneal cavity, permitting healing without risking contamination from external, percutaneous drainage.

The Effect of a Distal Centralizer on Cemented Femoral Stems in Arthroplasty Shown on Radiographs and SPECT/CT: A Case Report.

CASE: A 70-year-old female patient underwent total hip arthroplasty (HA) using a stem cemented line-to-line without centralizer. Postoperatively, she complained of load-dependent thigh pain. Conventional radiographs identified cortical overload because of a distal cement mantle discontinuity at the level of the stem's tip, confirmed by single-photon emission computed tomography/computed tomography scan (SPECT/CT). After cement-in-cement revision using a stem with centralizer, pain ceased rapidly. The cortical overload disappeared, as confirmed on a following SPECT/CT performed for low back pain. CONCLUSION: In HA, the stem's tip may cause overload on the bone's cortex if the cement mantle is incomplete. Implanting a stem with centralizer avoids or cures this.

Reconstruction of the Anterior Acetabular Wall to Repair Symptomatic Defects Consecutive to Cup Malpositioning at Total Hip Arthroplasty.

Iliopsoas impingement (IPI) causes persistent groin pain and functional impairment after total hip arthroplasty (THA). It is caused most often by an overhang of the cup. Psoas tenotomy may successfully treat IPI in overhangs <8 mm. Cup revision usually is recommended for larger overhangs. Muscle sparing reconstruction of the anterior acetabular wall may be an alternative when malposition of the cup at THA caused a bony defect that would persist after simple cup revision. The surgical technique and results from one patient are presented. The patient rapidly became asymptomatic and remained pain free at 2-year follow-up. Any bone substance defect of the acetabulum should be considered when evaluating treatment options for IPI after THA.

Anatomy of the lateral circumflex femoral artery: Does the direct anterior approach to the hip jeopardize vascularization of the proximal femur?

BACKGROUND: Blood supply of the proximal metaphysis of the femur comes mainly from the lateral circumflex femoral artery (LCFA). Essentially, the anterior approach has gained popularity in hip surgery but routinely requires the ligation of the ascending branch of the LCFA. Until now, there is no study analysing the effect of previous hip surgery on the vascularization of the proximal femur. Notably, it might, however, have consequences on osteointegration of uncemented prosthesis as well as in the management of early complications. Therefore we conducted a retrospective study to address the following questions: (1) Is the blood supply of the trochanteric region impaired by previous hip surgery, (2) does the anterior approach alter it more than other ones? HYPOTHESIS: We hypothesised that the surgical approach to the hip influences blood supply of the proximal femur, as visualised by retrospective analysis of femoral digital subtraction arteriograms (FDSA). PATIENTS AND METHODS: A retrospective review of 1280 FDSA, performed for vascular indications with a standard frame rate, between 07/2014 and 06/2016 in a single institution. Qualitatively sufficient FDSA were divided into 4 groups according to the history of previous hip surgery: hip replacement through an anterior approach (n=10) or through a lateral approach (n=31), cephalomedullary nailing for fractures of the proximal femur (n=5), and a control group of 50 continuous patients without previous hip surgery. The number of frames was counted between contrast injection into the femoral bifurcation and filling of the ipsilateral vessels of the greater trochanter to measure a potential delay/impairment of its arterial perfusion. Anatomic variations of the LCFA were also recorded. RESULTS: The number of frames between contrast injection and visualisation of the blood supply of the greater trochanter was 3.6±0.9 (mean±SD) in the control group (p<0.001 vs. all other groups). In patients with a hip replacement, the delay was 7.0±1.9 frames for the anterior approach and 5.2±1.1 frames for the lateral approach, respectively. In patients after cephalomedullary nailing, a delay of 4.8±1.5 frames was measured. The delay in the anterior approach group was significantly longer (p<0.001) compared to all other investigated groups. The ascending branch of the LCFA could not be detected after the anterior approach. As after lateral approach or as in the control group, the transverse branch was detectable in approximately 2/3 of the patients. DISCUSSION: Arterial perfusion of the greater trochanter is impaired after hip surgery, particularly after an anterior approach. The clinical relevance of these findings still needs to be investigated. It might, however, explain some early aseptic failures of uncemented stems. Moreover, it should be considered in early revision surgery, because combining different approaches might critically impair femoral blood supply. LEVEL OF EVIDENCE: III, retrospective case control study.

Prevalence and quantification of contamination of knitted cotton outer gloves during hip and knee arthroplasty surgery.

INTRODUCTION: Knitted cotton outer gloves offer protection against surgical glove perforation and provide improved grip on instruments. These gloves absorb blood and other fluids during surgery, and may therefore also accumulate contaminating bacteria. To date, there is no published data on microbial contamination of such gloves during surgery. METHODS: Knitted cotton outer gloves used in primary and revision hip and knee arthroplasty from two Swiss hospitals were analysed by quantitative bacteriology. Samples were subjected to sonication and vortexing, followed by membrane filtration of the sonicate. Membranes were incubated under aerobic and anaerobic culture conditions, respectively, for 21 days. Total microbial load for each pair of gloves was determined by colony-forming units (CFU) count. Strain identification was performed with MALDI-TOF. RESULTS: A total of 43 pairs of gloves were collected from continuous series of surgeries. Under aerobic culture conditions, total CFU counts ranged 0-1103, 25 (58%) samples remaining sterile, and 4 (9%) yielding > 100 CFU. Under anaerobic culture conditions, total CFU counts ranged 0-3579, 22 (51%) samples remaining sterile, 6 (14%) yielding > 100 CFU. The only covariate significantly associated with the level of contamination was the provider hospital (p < 0.0001 for aerobic and p = 0.007 for anaerobic cultures). Strain identification revealed only skin commensals, mainly coagulase-negative staphylococci and Propionibacterium spp. CONCLUSION: While contamination of surgical latex gloves is a well-known issue, no study has examined so far contamination of knitted cotton outer gloves. No or very low microbial contamination could be identified in the majority of the knitted cotton outer gloves assayed. However, a relevant proportion showed contamination far higher than estimated minimal thresholds for implant-associated infection. Clinical relevance of these findings remains to be established.

The Hip Lag Sign--prospective blinded trial of a new clinical sign to predict hip abductor damage.

This study introduces and validates the Hip Lag Sign, a new clinical parameter to determine hip abductor damage, which appears to be one major cause for greater trochanteric pain syndrome. 26 patients who underwent standardized MRI-examination were prospectively enrolledbetween October 2009 and March 2012. A standard physical examination of the hip was performed, including the Hip Lag Sign as it is defined for the first time in this work. Hip Lag Sign results were statistically compared toMR images, to pain levels measured with the visual analogue scale and to results of the modified Harris Hip Score as a universal and well established diagnostic tool for the hip. Chi2- and Mann-Whitney-U-analysis were applied. Diagnostic accuracy was tested with 2×2-table-calculations.Kappa statistics were used to analyze inter-observer variability. A positive Hip Lag Sign is significantly associated with MRI-proven hip abductor damage (p<0.001). The Hip Lag Sign has a sensitivity of 89.47% and a specificity of 96.55%. The positive and negative predictive values are 94.44%, resp. 93.33%. Its diagnostic Odds Ratio is 239.000 (p<0.001; 95%-CI: 20.031-2827.819). The number needed to diagnose was 1.16.Inter-observer consistency was 98.1% and kappa statistics for inter-observer variability were 0.911. The Hip Lag Sign is specific and sensitive, easy and fast to perform and allows a reliable assessment on the hip abductors' status, especially when there is no access to further diagnostic devices such as MRI for example due to restricted resources like in developing countries. Thus, we recommend the inclusion of the Hip Lag Sign into everyday hip examinations, especially dealing with patients suffering from greater trochanteric pain syndrome.

Hip MRI: how useful is intraarticular contrast material for evaluating surgically proven lesions of the labrum and articular cartilage?

OBJECTIVE: The objective of our study was to prospectively compare the diagnostic performance of MR arthrography and conventional MRI with surgical correlation in the same patient for detecting labrum and articular cartilage defects. SUBJECTS AND METHODS: Twenty-eight patients (mean age, 31.8 years) underwent MR arthrography, conventional MRI, and subsequent hip surgery, which served as the reference standard. Labrum and cartilage defects were evaluated at MRI by two independent readers. A McNemar test and kappa statistics were used for statistical analysis. RESULTS: At surgery, 31 labral tears were identified. MR arthrography had an advantage over conventional MRI for detecting labral tears at the anterosuperior quadrant (sensitivity of MR arthrography, 81% and 69% for readers 1 and 2, respectively; sensitivity of conventional MRI, 50% for both readers); this difference in performance between MR arthrography and conventional MRI was statistically significant for reader 1 (p = 0.02) but not for reader 2 (p = 0.2). Interobserver agreement for labral tears was higher for MR arthrography (κ = 0.81) than for conventional MRI (κ = 0.63). Surgery showed 31 acetabular cartilage defects and nine femoral cartilage defects. MR arthrography had an advantage over conventional MRI for detecting acetabular cartilage defects (sensitivity of MR arthrography, 71% and 92% for readers 1 and 2, respectively; sensitivity of conventional MRI, 58% and 83%), whereas there was no advantage to using MR arthrography for detecting femoral cartilage defects with statistically significant difference for the acetabular cartilage or femoral cartilage. Interobserver agreement was slightly higher for MR arthrography (κ = 0.50) than for conventional MRI (κ = 0.40) for assessing the acetabular cartilage and was almost identical for the femoral cartilage (κ = 0.62 and 0.63, respectively). CONCLUSION: MR arthrography was superior to conventional MRI for detecting labral tears and acetabular cartilage defects and showed a higher interobserver agreement. For femoral cartilage lesions, both modalities yielded comparable results.

Surgical hip dislocation versus hip arthroscopy for femoroacetabular impingement: clinical and morphological short-term results.

INTRODUCTION: Surgical hip dislocation (SHD) is an accepted standard to treat femoroacetabular impingement (FAI). However, arthroscopic techniques have gained widespread popularity and comparable results are reported. The purpose of this prospective comparative study was to test the hypothesis that, when compared to SHD, hip arthroscopy (HA) results in faster recovery, better short-term outcome, and equivalent morphological corrections. MATERIALS AND METHODS: 38 patients presenting with clinically and morphologically verified isolated FAI were allocated to either HA or SHD. Morphological evaluation consisted of pre- and postoperative X-rays, and arthro-MRI. Demographic data, sport activities, hospital stay, complications, and the time off work were recorded. The subjective hip value, WOMAC, HHS, and hip abductor strength were measured up to 1 year. RESULTS: Shorter hospital stay and time off work, less pain at 3 months and 1 year, higher subjective hip values at 6 weeks and 3 months, and better WOMAC at 3 months were seen after HA. The HHS and the hip abductor strengths were higher in the HA group. However, morphological corrections at the head-neck-junction achieved by HA showed some overcorrection when compared to SHD. Labral refixation was performed less frequent in the HA group. CONCLUSION: When compared to SHD, HA results in faster recovery and better short-term outcome. However, some overcorrection of the cam deformity and limited frequency of labrum refixation with HA in this study may have a negative impact on long-term outcome.

Abductor tendon tears are associated with hypertrophy of the tensor fasciae latae muscle.

OBJECTIVE: To evaluate the association between hypertrophy of the tensor fasciae latae muscle and abductor tendon tears. MATERIALS AND METHODS: Thirty-five patients who underwent MRI of the abductor tendons of the hip were included in this retrospective study. A subgroup of 18 patients was examined bilaterally. The area of the tensor fasciae latae muscle and the area of the sartorius muscle (size reference) were quantified at the level of the femoral head, and a ratio was calculated. Two radiologists assessed the integrity of the gluteus medius and minimus tendon in consensus. Data were analyzed with a Mann-Whitney U test. RESULTS: Sixteen out of 35 patients (46 %) had a tear of the gluteus medius or minimus tendon. The ratio of the area of the tensor fasciae latae to the sartorius muscle was significantly higher (p = .028) in the group with an abductor tendon tear (median 2.25; Interquartile Range [IQR] = 1.97-3.21) compared to the group without any tears (median 1.91; IQR = 1.52-2.26). The bilateral subanalysis showed that in patients without a tear, the ratio of the two areas did not differ between each side (p = .966), with a median of 1.54 (primary side) and 1.76 (contralateral side). In patients with an abductor tendon tear the ratio was significantly higher (p = .031) on the side with a tear (median 2.81) compared to the contralateral healthy side (1.67). CONCLUSION: Patients with abductor tendon tears showed hypertrophy of the tensor fasciae latae muscle when compared to the contralateral healthy side and to patients without a tear.

Closed suction drainage with or without re-transfusion of filtered shed blood does not offer advantages in primary non-cemented total hip replacement using a direct anterior approach.

INTRODUCTION: Wondering if the use of drains allowing re-transfusion of shed blood as opposed to closed suction drains or no drains would improve quality of care to patients undergoing simple non-cemented primary total hip replacement (THR) using a direct anterior approach, a three-arm prospective randomized study was conducted. METHOD: One hundred and twenty patients were prospectively randomized to receive no drain, closed suction drains or drains designed for re-transfusion of shed blood. Blood loss, VAS pain scores, thigh swelling, hematoma formation, number of dressings changed and hospital stay were compared and patients followed for 3 months. RESULTS: Drains did not have any significance on postoperative haemoglobin and haematocrit levels or homologous blood transfusion rates. Patients receiving homologous blood transfusions had too small drain volumes to benefit from re-transfusion and patients, who get drained fluid re-transfused, were far away from being in need of homologous blood transfusion. Omitting drains resulted in more thigh swelling accompanied with a tendency of slightly more pain during the first postoperative day but without effect on clinical and radiological outcome at 3 months. Earlier dry operation sites resulting in simplified wound care and shorter hospital stay was encountered when no drain was used. CONCLUSION: The possibility to re-transfuse drained blood was not an argument for using drains and, accepting more thigh swelling, we stop to use drains in simple non-cemented primary THR using the direct anterior approach.

Periacetabular osteotomy: validation of intraoperative fluoroscopic monitoring of acetabular orientation.

During periacetabular osteotomy (PAO) the acetabulum is reorientated and the correction monitored by one or more anteroposterior pelvic radiographs. Obtaining these images is time consuming and requires additional technical and personal resources. Such disadvantages could be overcome with the use of fluoroscopy. However, information obtained from fluoroscopy should have the same quality when compared to standard pelvic radiography. Our purpose was to define a suitable fluoroscopy setup and compare the information obtained from the fluoroscopic images to that obtained from a traditional anteroposterior pelvic radiograph. In a consecutive series of 22 patients the acetabular fragment was monitored by a defined intraoperative fluoroscopy setup in addition to a pelvic radiograph. The images were analyzed in random order utilizing common parameters to judge the quality of acetabular orientation. Agreement between the two images was assessed using kappa statistics and compared to the intra-observer reliability obtained from an independent experienced hip surgeon reading the same set of pelvic radiographs on two occasions. In 5 patients the radiation exposure during both fluoroscopy and standard AP pelvic radiography was measured and compared. Agreement of angular measurements of acetabular coverage and version as well as qualitative parameters of acetabular orientation and position between fluoroscopy and pelvic radiographs was at least equal to the intra-observer agreement of an independent experienced hip surgeon reviewing the pelvic radiographs alone. Significantly less radiation exposure was recorded with the use of fluoroscopy when compared to traditional pelvic radiography. We conclude that the use of intraoperative pelvic radiographs during PAO procedures can be replaced by fluoroscopy without quality impairment.

Radiographic markers of acetabular retroversion: correlation of the cross-over sign, ischial spine sign and posterior wall sign.

Radiological diagnosis of acetabular retroversion is based on the presence of the cross-over sign (COS), the posterior wall sign (PWS), and prominence of the ischial spine (PRISS). The primary purpose of the study was to correlate the quantitative cross-over sign with the presence or absence of the PRISS and PWS signs. The hypothesis was that both, PRISS and PWS are associated with a higher cross-over sign ratio or higher amount of acetabular retroversion. A previous study identified 1417 patients with a positive acetabular cross-over sign. Among these, three radiological parameters were assessed: (1) the amount of acetabular retroversion, quantified as a cross-over sign ratio; (2) the presence of the PRISS sign; (3) the presence of the PWS sign. The relation of these three parameters was analysed using Fisher's exact test, ANOVA, and linear regression analysis. In hips with cross-over sign, the PRISS was present in 61.7%. A direct association between PRISS and the cross-over sign ratio (p < 0.001) was seen. The PWS was positive in 31% of the hips and was also significantly related with the cross-over sign ratio (p < 0.001). In hips with a PRISS, 39.7% had a PWS sign, which was a significant relation (p < 0.001). In patients with positive PWS, 78.8% of the cases also had a PRISS (p < 0.001). Both the PRISS and PWS signs were significantly associated with higher grade cross-over values. Both the PRISS and PWS signs as well as the coexistence of COS, PRISS, and PWS are significantly associated with higher grade of acetabular retroversion. In conjunction with the COS, the PRISS and PWS signs indicate severe acetabular retroversion. Presence and recognition of distinct radiological signs around the hip joint might raise the awareness of possible femoroacetabular impingement (FAI).

MR arthrography of the hip: differentiation between an anterior sublabral recess as a normal variant and a labral tear.

PURPOSE: To retrospectively evaluate imaging characteristics of surgically proved sublabral recesses and labral tears in the anterior portion of the acetabulum at magnetic resonance (MR) arthrography. MATERIALS AND METHODS: Institutional review board approval was obtained; informed consent was waived. The study included 57 patients (36 women [mean age, 37 years], 21 men [mean age, 32 years]) who underwent MR arthrography and either surgery or arthroscopy as reference standard. On MR images, location of sublabral contrast material interposition and depth, shape, and extension into the labral substance of contrast material interpositions were described. Abnormal labral signal intensity (areas of high signal intensity), acetabular cartilage lesions, osseous abnormalities, and perilabral cysts were noted. Mann-Whitney U and Fisher exact tests were performed; interobserver agreement was calculated (kappa statistic and intraclass correlation coefficient). RESULTS: Surgical procedures revealed that 10 (18%) of 57 patients had recesses and 44 (77%) of 57 had tears. Locations of recesses and tears, respectively, were as follows: seven and none, in the 8-o'clock position; two of each, in the 9-o'clock position; one and 22, in the 10-o'clock position; and none and 20, in the 11-o'clock position. None of the recesses extended into the substance of the labrum or through the full thickness of the labral base; 51% (22 of 43) of tears extended into the substance and 49% (21 of 43) of tears extended along the entire labral base. Shape of sublabral contrast material interposition was linear in five (83%) of six recesses and 21 (49%) of 43 tears. Recesses were not associated with abnormal signal intensity of the labrum, cartilage lesions, osseous abnormalities, or perilabral cysts. Of 43 tears, 32 (74%) were associated with abnormal signal of the labrum; 23 (53%), with cartilage damage; 11 (26%), with osseous abnormalities; and eight (19%), with perilabral cysts. CONCLUSION: Recesses occur as normal variants in the anteroinferior part of the acetabulum. Location in the 8-o'clock position, linear shape of contrast material interposition, partial separation of the labrum, and absence of perilabral abnormalities are characteristics of a recess.

Evaluation of intratester and intertester reliability of the Constant-Murley shoulder assessment.

This study evaluated the reliability of the Constant-Murley Score. Two testers assessed 63 patients twice on the same day using the original publication by Constant and Murley. The intratester reliability of the total score was high and the differences between the tests were small; 2 of 14 items were unreliable. The intertester reliability was high, but there were significant median differences of the total score; 12 of 14 items were unreliable. We believe that the differences between the testers were due to the brief explanations of test components in the original publication. The reliability of the Constant-Murley Score could possibly be improved by a better standardization of the assessment procedure.

Ischial spine projection into the pelvis : a new sign for acetabular retroversion.

Femoroacetabular impingement may occur in patients with so-called acetabular retroversion, which is seen as the crossover sign on standard radiographs. We noticed when a crossover sign was present the ischial spine commonly projected into the pelvic cavity on an anteroposterior pelvic radiograph. To confirm this finding, we reviewed the anteroposterior pelvic radiographs of 1010 patients. Nonstandardized radiographs were excluded, leaving 149 radiographs (298 hips) for analysis. The crossover sign and the prominence of the ischial spine into the pelvis were recorded and measured. Interobserver and intraobserver variabilities were assessed. The presence of a prominent ischial spine projecting into the pelvis as diagnostic of acetabular retroversion had a sensitivity of 91% (95% confidence interval, 0.85%-0.95%), a specificity of 98% (0.94%-1.00%), a positive predictive value of 98% (0.94%-1.00%), and a negative predictive value of 92% (0.87%-0.96%). Greater prominence of the ischial spine was associated with a longer acetabular roof to crossover sign distance. The high correlation between the prominence of the ischial spine and the crossover sign shows retroversion is not just a periacetabular phenomenon. The affected inferior hemipelvis is retroverted entirely. Retroversion is not caused by a hypoplastic posterior wall or a prominence of the anterior wall only and this finding may influence management of acetabular disorders.

Articular cartilage defects detected with 3D water-excitation true FISP: prospective comparison with sequences commonly used for knee imaging.

PURPOSE: To prospectively compare the accuracy of three-dimensional (3D) water-excitation (WE) true fast imaging with steady-state precession (FISP) in the diagnosis of articular cartilage defects with that of sequences commonly used to image the knee, with arthroscopy or surgery as the reference standard. MATERIALS AND METHODS: This study protocol was institutional review board approved. Written informed consent was obtained from all patients. Thirty knees in 29 patients (mean age, 56 years; range, 18-86 years) were prospectively evaluated by using sagittal 3D WE true FISP with two section thicknesses (1.7 mm [true FISPthin] and 3.0 mm [true FISPthick]), two-dimensional (2D) intermediate-weighted spin-echo with fat saturation, 2D fast short inversion time inversion-recovery, 3D WE double-echo steady-state, and 3D fat-saturated fast low-angle shot sequences. Cartilage defects were graded on magnetic resonance images and during surgery with a modified Noyes scoring system. Contrast-to-noise ratio (CNR) and CNR efficiency were calculated. Sensitivity, specificity, and accuracy were assessed. Interobserver agreement was determined with kappa statistics, and quantitative results were evaluated with the Wilcoxon signed rank test. RESULTS: The performance of 3D WE true FISPthick (sensitivity, specificity, and accuracy, respectively, were 52%, 93%, and 71% for reader 1 and 65%, 88%, and 76% for reader 2) and 3D WE true FISPthin (sensitivity, specificity, and accuracy, respectively, were 58%, 94%, and 75% for reader 1 and 63%, 80%, and 71% for reader 2) sequences was no different than that of other sequences in the detection of circumscribed defects. Three-dimensional WE true FISP sequences had a significantly (P<.0033) higher CNR and CNR efficiency between cartilage and fluid than the corresponding sequences with the same section thickness. CONCLUSION: Three-dimensional WE true FISP enables high contrast between joint fluid and articular cartilage and a diagnostic performance that is comparable with that of standard sequences.

Cam and pincer femoroacetabular impingement: characteristic MR arthrographic findings in 50 patients.

PURPOSE: To retrospectively characterize magnetic resonance (MR) arthrographic findings in patients with cam femoroacetabular impingement (FAI) and in those with pincer FAI. MATERIALS AND METHODS: Institutional review board approval and informed consent were not required. MR arthrographic studies obtained in 50 consecutive patients (30 men, 20 women; mean age, 28.8 years) with FAI were analyzed for labral abnormalities, cartilage lesions, and osseous abnormalities of the acetabular rim. The nonspherical shape of the femoral head at the head-neck junction was measured in eight positions around the femoral head and neck and used to calculate the alpha angle. Acetabular depth was measured. Surgical diagnosis served as the reference standard. The Wilcoxon rank sum test was used for statistical analysis. RESULTS: At surgery, hips in 33 patients were classified as having cam FAI and hips in 17 patients were classified as having pincer FAI. In both groups, the mean age of patients was 28.8 years. There were significantly more men (n = 27) with cam FAI and more women (n = 14) with pincer FAI. The alpha angle was significantly larger in patients with cam FAI at the anterior and anterosuperior positions. The acetabulum was significantly deeper in patients with pincer FAI than in patients with cam FAI. Cartilage lesions at the anterosuperior and superior positions were significantly larger in patients with cam FAI than in patients with pincer FAI. Cartilage lesions at the posteroinferior position were significantly larger and labral lesions at the posterior and posteroinferior positions were more pronounced in patients with pincer FAI than in patients with cam FAI. Osseous abnormalities were not significantly different between the groups. Osseous bump formation at the femoral neck was significantly more common in patients with cam FAI than in patients with pincer FAI. CONCLUSION: Characteristic MR arthrographic findings of cam FAI include large alpha angles and cartilage lesions at the anterosuperior position and osseous bump formation at the femoral neck; characteristic findings of pincer FAI include a deep acetabulum and posteroinferior cartilage lesions.

The course of macroscopic degeneration in the human lumbar intervertebral disc.

STUDY DESIGN: Assessment of age-related macroscopic changes in human lumbar intervertebral discs (IVD) and vertebral bodies. OBJECTIVES: To determine the sequence of macroscopic changes during aging/degeneration. SUMMARY OF BACKGROUND DATA: Descriptive studies on macroscopic alterations of the IVD during aging/degeneration are readily available, but quantitative analyses are sparse. METHODS: A total of 248 mid-/parasagittal sections of lumbar IVD and vertebral bodies from 41 routine autopsies (range, 7 months to 88 years) were semiquantitatively assessed for macroscopic parameters and correlated with age. RESULTS: Nuclear fibrous transformation, anular disorganization, endplate, and vertebral body alterations progress predominantly in the first two and in the fifth to seventh decades. In the third and fourth decade, little progression occurs. Nuclear clefts and anular tears appear later, mostly starting in the second decade, with clefts preceding tear formation. Radial and concentric tears develop similarly over time, whereas rim lesions mostly develop after the sixth decade. Significant differences are observed between upper and lower lumbar spine. CONCLUSION: Our data show that fibrous nuclear transformation during aging/degeneration precedes cleft formation. The temporal sequence suggests a strong correlation of cleft and tears formation starting with clefts in the second decade. Our results support the hypothesis that disc degeneration starts in the nucleus. Extensive macroscopic alterations already apparent in the second life decade present a challenge to any tissue engineering and repair attempt.

Mechanical strength of arthroscopic rotator cuff repair techniques: an in vitro study.

BACKGROUND: Retears after rotator cuff repairs occur relatively frequently and may compromise the functional result. The goal of this study was to analyze the mechanical properties following arthroscopic techniques for rotator cuff repair and to evaluate possible alternative techniques. METHODS: In the first part, five different bone anchors (the Revo screw; Mitek Rotator Cuff anchor, 5.0-mm Statak, PANALOK RC absorbable anchor, and 5.0-mm Bio-Statak) were tested in vitro under cyclic loading on five pairs of cadaveric shoulders. Then five types of arthroscopic tendon suturing instruments were tested on rotator cuff tendons. Finally, the arthroscopically performed mattress and modified Mason-Allen stitches, fixed with either the Revo screw or the Bio-Statak, were evaluated on ten pairs of human cadaveric shoulders. RESULTS: The holding strengths of the various anchors were similar, ranging from 130 to 180 N, and approximated the holding strength of knotted number-2 suture materials. The fixation of the tested anchors yielded comparable values of stiffness except for one anchor, which showed significantly greater subsidence under cyclic load (p = 0.003). All tested, commercially available arthroscopic suturing devices were unsuitable for performing a modified Mason-Allen stitch on normal supraspinatus tendons. Modification of a commercially available suture punch with a longer needle allowed us to consistently perform a modified Mason-Allen stitch. The modified Mason-Allen stitch, which has shown favorable mechanical properties in open repairs of the rotator cuff, was not found to be stronger than the mattress stitch when performed arthroscopically and used with bone anchors. When the modified Mason-Allen stitch was fixed to one anchor, it was even weaker than a mattress stitch repaired with another anchor (168 versus 228 N). Unequal loading of the two suture branches due to the more rigid modified Mason-Allen stitch may be the reason for this difference. CONCLUSIONS: Arthroscopic techniques for rotator cuff repair with use of the mattress stitch and bone anchors allow for a relatively solid fixation. The holding strength is not improved with use of the modified Mason-Allen stitch. Although a direct comparison with previous in vitro studies is not possible, the holding strength of open fixation techniques seems to be stronger. If rotator cuffs are subjected to high postoperative loading, open repair might be preferred to reduce the risk of a retear, until stronger arthroscopic fixation techniques are developed.

Retroperitoneal Endoscopically Assisted Minilaparotomy for Anterior Lumbar Interbody Fusion: Technical Feasibility and Complications.

STUDY DESIGN: Description of a novel less invasive technique and prospective evaluation of associated morbidity and potential complications. OBJECTIVE: To investigate the feasibility of a novel endoscope-assisted retroperitoneal approach (REAM) for anterior lumbar interbody fusion (ALIF). SUMMARY OF BACKGROUND DATA: Minimally and less invasive approaches are currently favored to perform ALIF. However, the present endoscopic techniques have not found widespread acceptance, because they are technically demanding, and microsurgical techniques are not time effective when two separate approaches are needed for L5-S1 (transperitoneal) and L4-L5 (retroperitoneal). METHODS: The authors have developed the technique of REAM, which consists of three stages: 1) endoscopic retroperitoneal mobilization of the peritoneal sac, 2) midline minilaparotomy (4-6 cm), and 3) standard open anterior lumbar interbody fusion. Twenty patients were prospectively enrolled in this study and perioperative data (i.e., blood loss, operative time, intra- and postoperative complications) were collected to assess the feasibility of this approach. RESULTS: Six single-level and 14 two-level ALIFs from L3-L4 to L5-S1 were performed with a mean operative time of 108 minutes (range, 85-150) and an average estimated blood loss of 200 mL (range, 50-500). The follow-up (range, 12-29 months) on 20 patients showed that there were no perioperative or postoperative complications related directly to this approach. CONCLUSION: Anterior lumbar interbody fusion by REAM can be performed without additional hazard to the patient and appears to be a reasonable alternative to existing less invasive procedures.