Outcomes of surgical management for tarsal coalitions: a systematic review.

PURPOSE: To analyze the outcome of surgical treatment of tarsal coalition, assess the role of the surgical technique, as well as of coalition size and type on outcomes. METHODS: The search followed the Preferred Reporting Items of Systematic Review and Meta-Analysis and was performed in four databases: MEDLINE, Central, Scopus and Web of Science. The protocol has been registered in the international prospective register of systematic reviews. Patient-reported outcomes (PROMs), complications, revisions and radiographic recurrence were collected. Risk of bias was assessed using MINORS criteria. A random-effects model for meta-analysis was applied for analysis of data heterogeneity. RESULTS: Twenty-five studies including 760 tarsal coalitions were included and had a weighted average follow-up of 44 months. Studies scored fair to poor on the risk of bias assessment with a mean MINORS score of 67% (44-81%). In 77.8% (37.5-100%) of surgically treated tarsal coalitions, good/excellent/non-limiting or improved PROMs were reported. Calculated data heterogeneity was moderate (I2 = 57%). Open bar resection with material interposition had a clinical success rate of 78.8% (50-100%). Complications occurred in 4.96% of cases. Coalition size did not prove to be a determining factor in postoperative outcome. The influence of the coalition type was not investigated by any of the studies. CONCLUSION: Data on outcomes of surgical management for tarsal coalitions is limited to retrospective case series with high risk of bias and moderate data heterogeneity. In about ¾ of cases, open resection and interposition of material results in improved PROMs. The arbitrary margin of ≥ 50% of TC coalition size in relation to the posterior facet has little importance in surgical decision-making. None of the studies reported on the influence of the coalition type on postoperative clinical success.

Achieving high union rates after first metatarsophalangeal joint arthrodesis: Radiographic outcomes and technical pitfalls.

BACKGROUND: Fusion of the first metatarsophalangeal (MTP1) joint is a common surgery performed to correct hallux rigidus, hallux rigidus et valgus and other painful degenerative diseases of the MTP1. AIM: To assess outcomes of our surgical technique including non-union rates, accuracy and aims of correction. METHODS: Between September 2011 and November 2020 a total 72 of MTP1 fusions were performed using a low profile, pre-contoured dorsal locking plate and a plantar compression screw. Union and revision rates were analyzed with a minimum clinical and radiological follow up of at least 3 mo (range 3-18 mo). The following parameters were evaluated on pre- and postoperative conventional radiographs: Intermetatarsal angle, Hallux-valgus angle, dorsal extension of the proximal phalanx (P1) in relation to the floor and the angle between the Metatarsal 1 and the P1 (MT1-P1 angle). Descriptive statistical analysis was performed. Pearson analysis was used to assess for correlations between radiographic parameters and achievement of fusion. RESULTS: An overall union rate of 98.6% (71/72) was achieved. Two out of 72 patients did not primarily fuse with one patient suffering from a non-union, whilst the other demonstrating a radiological delayed union without clinical symptoms, with eventually complete fusion after 18 mo. There was no correlation between the measured radiographic parameters and the achievement of fusion. We believe the reason for the non-union was mainly attributed to the patient's incompliance without wearing the therapeutic shoe leading to a fracture of the P1. Furthermore, we didn`t find any correlation between fusion and the degree of correction. CONCLUSION: With our surgical technique, high union rates (98%) can be achieved using a compression screw and a dorsal variable-angle locking plate to treat degenerative diseases of the MTP1.

Correlation between preoperative clinical examination and intraoperatively found subscapularis tendon tear.

PURPOSE: Analyze the diagnostic value for subscapularis (SSC) tendon tears, their correlation between pain and strength on clinical tests, and compare them with intraoperative arthroscopic findings to prove their diagnostic value. METHODS: 110 consecutive patients undergoing arthroscopic rotator cuff repair were reviewed and allocated to isolated SSC (n = 39) and combined anterosuperior tendon tear (n = 71) groups and analyzed. Preoperative clinical testing included belly press (BPT), bear hug (BHT), lift-off (LOT), palm-up (PUT), and Jobe test (JT). All tests were performed in two categories: pain (in 4 categories: 0, 5, 10, and 15) and strength (from 0 to 5). The tendon tears were intraoperatively reviewed and classified. RESULTS: Mean age was 59 years (SD 10). The sensitivity of the BHT was 88.2% and 74.5% for BPT, while specificity was only 41.9% for BHT and 45% for BPT. Sensitivity of JT was 90.5% and 87.5% for PUT, while specificity was only 41% for JT and 28.2% for PUT. A low positive correlation for an intraoperative SSC lesion and the strength of BPT (Spearman rank correlation - 0.425; p value < 0.0001) and the strength of BHT ( - 0.362; p value = 0.001) could be found. With linear regression analysis estimated by ordinary least squares, a correlation between BPT strength and surgical grade of SSC lesion (- 0.528; 95% CI, - 0.923 to - 0.133; pvalue < 0.01) was found. CONCLUSION: The BHT showed a higher sensitivity for a SSC lesion, while the BPT had a higher correlation between preoperative testing, most notably internal rotation strength, and intraoperative surgical grade of the SSC tendon lesion. LEVEL OF EVIDENCE: Level II, Prospective cohort study for Diagnostic tests.

Postoperative fever: differences between elective vs. traumatic hip, knee and shoulder arthroplasty.

BACKGROUND: It is unclear whether there is a difference in the incidence of postoperative fever (POF) between hip, knee and shoulder arthroplasty. The influence of a trauma setting has not been investigated. METHODS: A retrospective review was performed on 675 joint replacement surgeries (hip, knee, shoulder arthroplasty) in an elective or trauma setting over a 2 year period (2016-2018). Patient demographics and perioperative/postoperative parameters were investigated. The fever curve was characterized. The results and costs of any fever-related diagnostic workup were reviewed. RESULTS: A total of 89 patients (13.2%) experienced a POF ≥ 38.0 °C, only 21 patients (3.1%) a POF ≥ 38.5 °C (of the latter: 4.6% of hip arthroplasties, 0.6% of knee arthroplasties, 0% of shoulder arthroplasties). There was a significantly greater risk (OR 3.88) for POF ≥ 38.5 °C in trauma total hip arthroplasty (THA) compared to elective THA (10.6 vs. 3.0%; p < 0.01). Differences in POF rate between the various joint areas were statistically insignificant when comparing only elective and trauma cases with each other, even though there was a trend for higher rates in hip surgery. Patients experiencing POF ≥ 38.5 °C were more often males (p < 0.01) and had an increased intraoperative blood loss (p = 0.03) and longer hospital stay (p < 0.01). There was only 1/89 POF patients developing an early periprosthetic joint infection. The cost of a positive fever workup (3/27 patients, 11.1%) leading to a new diagnosis and treatment was 2045 US$. CONCLUSION: POF ≥ 38.5 °C was more frequent in traumatic THA compared to elective THA. A trend of difference between POF rates between the different joint areas was statistically insignificant after separating elective and traumatic cases. The risk of developing an early periprosthetic joint infection was not increased in POF. A fever-related diagnostic workup was rarely helpful in the absence of clinical symptoms.

Nonoperatively managed small- to medium-sized subscapularis tendon tears: magnetic resonance imaging evaluation with a minimum of 5 years of follow-up.

BACKGROUND: Isolated or combined subscapularis (SSC) tendon tears are frequently found in patients with shoulder pain. The purpose of this study was to evaluate the structural changes associated with SSC tear in a consecutive series of patients with nonoperatively treated small size to midsize SSC tendon tears using magnetic resonance imaging (MRI). METHODS: In this retrospective case series, all patients with an isolated or combined SSC tendon tear treated nonoperatively between 1999 and 2019 were identified from our MRI and clinical databases. Twenty-one patients with a mean age of 52.6 years (range 26.6-64.8, standard deviation 9.3) with a second MRI scan at a minimum of 5 years of follow-up were enrolled. The mean follow-up was 8.6 years (range 5.6-12.6, standard deviation 1.8). Initial and last follow-up MRI scans were used to determine concomitant cuff lesions, size of the SSC tear, fatty infiltration of the SSC muscle, and biceps pathology. RESULTS: Five patients had an isolated SSC lesion; 7 patients had a concomitant tear of the supraspinatus, and 9 patients had a supraspinatus and anterior infraspinatus tendon tear. At diagnosis, 14 patients had a type 1 SSC lesion as classified by Lafosse et al, 4 patients had type 2, and 3 patients had type 3 lesions. Nineteen patients (90%) were found to have an SSC tear progression of at least one Lafosse grade (P < .001); however, no tear had progressed to an irreparable type lesion (defined as Lafosse type 5). In addition, the size of SSC tendon tears increased significantly from 75 mm2 to 228 mm2 (P < .001). At the final MRI scan, the grading of fatty infiltration increased by 1 grade in 4 cases and by 2 grades in 4 cases (P = .042). At the final follow-up, in eight patients, the condition of the long head of biceps tendon was unchanged from the initial MRI; in nine patients, there was a newly subluxated biceps tendon, and in 6 patients, there was a newly ruptured long head of biceps tendon (P < .001). CONCLUSION: After a mean of 8.6 years, almost all nonoperatively treated SSC tendon tears had increased in size, but only one-third showed additional progression of muscle fatty degeneration on MRI scan. None of the SSC lesions became irreparable during the observation period.

The Metatarsal Cortical Index as an Indicator of Insufficiency Fracture of the Foot.

The diagnosis of metatarsal stress fractures is challenging. Standard imaging often shows false-negative results. The aim of this study was to create reliable radiologic outcome parameters to predict insufficiency fractures of the metatarsals. We performed an age- and sex-matched case-control study of patients with (n = 18) and without insufficiency fracture (n = 18) of the foot. The metatarsal cortical index (MCI) for each metatarsal was developed to predict an insufficiency fracture. The MCI of each metatarsal was significantly decreased in the insufficiency fracture group compared with the control group (p < .01). The MCI of the fourth ray yielded the highest area under the curve among the analyzed MCI values (area under the curve, 0.79; 95% confidence interval, 0.61-0.90). A cut-off value of 1.62 for the MCI of the fourth ray yielded a sensitivity of 78% and a specificity of 78% to predict insufficiency fracture of the foot (odds ratio, 12.25; 95% confidence interval, 2.54-58.97), and enabled accurate allocation to the insufficiency fracture group versus the control group in 74% of cases. In conclusion, a decreased MCI is associated with metatarsal insufficiency fractures and enables an accurate diagnosis in 3 out of 4 cases. The MCI might aid clinicians in identifying insufficiency fracture, and raise the suspicion of the diagnosis without additional imaging studies.

The interphalangeal angle as a novel radiological measurement tool for Morton's neuroma - a matched case-control study.

BACKGROUND: The aim of this retrospective study was to examine if a correlation between Morton's Neuroma (MN) and an increased interphalangeal angle (IPA) or intermetatarsal angle (IMA) can be found in preoperative weightbearing dorsal-plantar X-rays of the foot. METHODS: Forty-five patients with forty-nine MN in the interspaces 2/3 or 3/4 and 49 controls were recruited for this study. Every MN was matched with an asymptomatic control without history of metatarsalgia. The diagnosis was made by clinical examination, magnetic resonance imaging (MRI) and positive histopathology after operative resection. IMA 1/5, 2/3, 2/4, 2/5, 3/4 and IPA 2/3, 3/4 were measured for both groups. RESULTS: The IPA 3/4 was significantly enlarged by 2.8 degrees (p < 0.001) with Area under the curve (AUC) 0.75 (p < 0.001), sensitivity of 73% and specificity of 67% in feet with MN compared to controls. The IMA 3/4 was significantly enlarged by 1 degree (p < 0.048) with AUC 0.64 (p < 0.031), sensitivity of 71% and specificity of 43% in feet with MN compared to controls. No difference between IMA 2/4, 2/5, 1/5 or correlation between IPA or IMA and the size of the MN in the MRI was found. CONCLUSION: The results confirm the clinical observation of an increased IPA in patients with MN. An increased IPA should therefore be considered in the diagnosis of MN.

Revision rate of THA in patients younger than 40 years depends on primary diagnosis - a retrospective analysis with a minimum follow-up of 10 years.

BACKGROUND: Treating osteoarthritis in elderly patients with THA is very successful. However, surgeons hesitate to recommend THA in younger patients. The spectrum of etiologies for end stage hip disease in the younger population is diverse and therefore different courses may be assumed. Our objective was to evaluate THA revision rate within a minimum follow-up period of 10 years in young patients and to analyze the difference between different primary diagnoses. METHODS: We included 144 consecutive hips in 127 patients younger than 40 years, who received a primary THA from 01/1996 to 12/2007. Operative reports, clinical and radiographic documentation were reviewed to determine primary diagnosis, prior hip surgery, component specifications and revision surgery. 111 hips in 97 patients were available for outcome analysis with a minimum follow-up of 10 years. RESULTS: The mean age was 33 years (range 15-40 years) at the time of the index THA, 68 patients were female and 59 were male. Ten years revision rate on the prosthetic components was 13%. The most common primary diagnosis was DDH. DDH was associated with a risk of 17% for requiring a reoperation on the prosthetic components because of mechanical fatigue and therefore, significantly higher than for any other primary diagnosis (p = 0.005). CONCLUSION: THA in young patients is associated with a high revision rate of 13% in 10 years. 17% of patients with DDH required revision surgery for mechanical fatigue within 10 years, which was significantly higher than for any other primary diagnosis (1.2%, OR 16.8).

Mid-term results after in situ pinning and hip arthroscopy for mild slipped capital femoral epiphysis: a minimum five-year follow-up.

PURPOSE: In situ pinning of mild slipped capital femoral epiphysis (SCFE) results in an aspherical head-neck junction and arthroscopic osteochondroplasty can successfully correct the head-neck junction. However, whether the correction stays stable over at least five years remains unknown. METHODS: In a retrospective and consecutive series, 11 patients with a mean age of 12 years (range, 10 years to 15 years) were included. All patients were treated for mild SCFE with in situ pinning and staged hip arthroscopy correcting the head-neck junction. All patients were assessed clinically and radiographically (radiograph and magnetic resonance imaging (MRI)) pre-operatively, 12 weeks and at least five years' post-operatively. RESULTS: The mean range of motion (ROM) for flexion and internal rotation was stable over time with 100° (sd 4) and 21° (sd 6), respectively at the last follow-up. The mean alpha angle decreased from pre-operative 64° (range 61° to 68°) to 12 weeks post-operative 49° (range 46° to 52°; p = 0.001) and stayed stable over time. New superficial cartilage damage on either the acetabular or femoral side was seen in each three patients. Progressive labral degeneration was present in two patients. CONCLUSION: In situ pinning and staged hip arthroscopy for the correction of mild SCFE is safe, restores normal alpha angles and reveals stable morphological correction at mid-term follow-up. Furthermore, the clinical results were excellent with almost normalized internal hip rotation at mid-term follow-up in patients who had reached adulthood. However, there was some joint deterioration, but without negative impact on subjective and clinical outcome after at least five years. LEVEL OF EVIDENCE: IV.

Combined Correction of Tibial Torsion and Tibial Tuberosity-Trochlear Groove Distance by Supratuberositary Torsional Osteotomy of the Tibia.

BACKGROUND: Increased external tibial torsion and tibial tuberosity-trochlear groove distance (TTTG) affect patellofemoral instability and can be corrected by tibial rotational osteotomy and tibial tuberosity transfer. Thus far, less attention has been paid to the combined correction of tibial torsion and TTTG by supratuberositary osteotomy. PURPOSE: To quantify the effect of a supratuberositary torsional osteotomy on TTTG. STUDY DESIGN: Descriptive laboratory study. METHODS: Seven patients who underwent supratuberositary osteotomy to treat patellofemoral instability and an additional 13 patients with increased TTTG were included (N = 20). With 3-dimensional (3D) surface models, supratuberositary rotational osteotomies were simulated with predefined degrees of rotation. Concomitant 3D TTTG was measured by a novel and validated measurement method. In addition, all operated patients underwent 2-dimensional (2D) radiographic evaluation with pre- and postoperative computed tomography data. Absolute differences among simulated, predicted, and achieved postoperative corrections were compared. RESULTS: A total of 500 supratuberositary osteotomies were simulated. The linear regression estimate yielded a change of -0.68 mm (95% CI, -0.72 to -0.63; P < .0001) in 3D TTTG per degree of tibial rotation, and 2D and 3D TTTG measurements in the operated patients were comparable in pre- and postoperative measurements (preoperative, 19.8 ± 2.5 mm and 20.0 ± 2.4 mm; postoperative, 13.6 ± 3.8 mm and 14.6 ± 3.4 mm, respectively). Postoperative 2D TTTG deviated in absolute terms from predicted (regression) and simulated TTTG by 1.4 ± 1.0 mm and 1.5 ± 0.6 mm. Inter- and intrarater reliability (intraclass correlation coefficient) for radiological and simulated measurements ranged between 0.883 and 0.996 and were almost perfect. CONCLUSION: In supratuberositary osteotomy, TTTG changes by -0.68 mm per degree of internal tibial rotation. The absolute mean difference between postoperative predicted TTTG and 2D TTTG was only 1.4 mm. Thus, TTTG correction can be successfully predicted by the degree of tibial rotation. CLINICAL RELEVANCE: TTTG correction can be successfully predicted by the degree of tibial rotation. Therefore, in selected cases, tibial torsional deformity and TTTG can be corrected by 1 osteotomy. However, isolated rotations have been performed, and unintended translational movements during tibial rotation may alter the postoperative results.

Assessing the effects of intratendinous genipin injections: Mechanical augmentation and spatial distribution in an ex vivo degenerative tendon model.

BACKGROUND: Tendinopathy is a common musculoskeletal disorder and current treatment options show limited success. Genipin is an effective collagen crosslinker with low cytotoxicity and a promising therapeutic strategy for stabilizing an intratendinous lesion. PURPOSE: This study examined the mechanical effect and delivery of intratendinous genipin injection in healthy and degenerated tendons. STUDY DESIGN: Controlled laboratory study. METHODS: Bovine superficial digital flexor tendons were randomized into four groups: Healthy control (N = 25), healthy genipin (N = 25), degenerated control (N = 45) and degenerated genipin (N = 45). Degeneration was induced by Collagenase D injection. After 24h, degenerated tendons were subsequently injected with either 0.2ml of 80mM genipin or buffer only. 24h post-treatment, samples were cyclically loaded for 500 cycles and then ramp loaded to failure. Fluorescence and absorption assays were performed to analyze genipin crosslink distribution and estimate tissue concentration after injection. RESULTS: Compared to controls, genipin treatment increased ultimate force by 19% in degenerated tendons (median control 530 N vs. 633 N; p = 0.0078). No significant differences in mechanical properties were observed in healthy tendons, while degenerated tendons showed a significant difference in ultimate stress (+23%, p = 0.049), stiffness (+27%, p = 0.037), work to failure (+42%, p = 0.009), and relative stress relaxation (-11%, p < 0.001) after genipin injection. Fluorescence and absorption were significantly higher in genipin treated tendons compared to control groups. A higher degree of crosslinking (+45%, p < 0.001) and a more localized distribution were observed in the treated healthy compared to degenerated tendons, with higher genipin tissue concentrations in healthy (7.9 mM) than in degenerated tissue (2.3 mM). CONCLUSION: Using an ex-vivo tendinopathy model, intratendinous genipin injections recovered mechanical strength to the level of healthy tendons. Measured by genipin tissue distribution, injection is an effective method for local delivery. CLINICAL RELEVANCE: This study provides a proof of concept for the use of intratendinous genipin injection in the treatment of tendinopathy. The results demonstrate that a degenerated tendon can be mechanically augmented by a clinically viable method of local genipin delivery. This warrants further in vivo studies towards the development of a clinically applicable treatment based on genipin.

Radiographic performance depends on the radial glenohumeral mismatch in total shoulder arthroplasty.

BACKGROUND: Optimal radii of curvature of the articulating surfaces of the prosthetic components are factors associated with the longevity of cemented glenoid components in anatomical total shoulder arthroplasty. It was the purpose of this study, to evaluate the radiographic and clinical performance of an anatomical glenoid component of a total shoulder arthroplasty (TSA) with respect to radial mismatch of the glenoid and humeral component. METHODS: In a retrospective study 75 TSA were analyzed for their clinical and radiographic performance with computed tomography by independent examiners using an established methodology. The study group was divided in two groups, one with mismatch < 4.5 mm (n:52) the others with mismatch ≥4.5 mm (n:23) and analyzed for confounding variables as indication, primary or revision surgery, age, gender, glenoid morphology and implant characteristics. RESULTS: The mean glenohumeral radial mismatch was 3.4 mm (range 0.5-6.9). At median follow-up of 41 months (range 19-113) radiographic loosening (defined as modified Molé scores ≥6) was present in 7 cases (9.3%). Lucencies around the glenoid pegs (defined as modified Molé score ≥ 1) were present in 34 cases (45%). Radiolucencies were significantly associated with a radial mismatch < 4.5 mm (p = 0.000). The pre- to postoperative improvements in Subjective Shoulder Value and absolute Constant Score were significantly better in the group with a mismatch ≥4.5 mm (p = 0.018, p = 0.014). CONCLUSION: A lower conformity of the radii of humerus and glenoid seems to improve the loosening performance in TSA. Perhaps cut-off values regarding the recommended mismatch need to be revalued in the future.

Mid-term walking ability after Charcot foot reconstruction using the Ilizarov ring fixator.

BACKGROUND: Failed conservative treatment and complications are indications for foot reconstruction in Charcot arthropathy. External fixation using the Ilizarov principles offers a one-stage procedure for deformity correction and resection of osteomyelitic bone. The aim of this study was to determine whether external fixation with an Ilizarov ring fixator leads reliably to walking ability. MATERIALS AND METHODS: 29 patients treated with an Ilizarov ring fixator for Charcot arthropathy were retrospectively analyzed. Radiologic fusion at final follow up was assessed separately on conventional X-rays by two authors. The association between walking ability and the presence of osteomyelitis at the time of reconstruction, and the presence of fusion at final follow up was investigated using Fisher's exact test. RESULTS: Mean follow up was 35 months (range 5.3-107) months; mean time of external fixation was 113 days. Ten patients (34.5%) reached fusion, but 19 did not (65.5%). Two patients needed below knee amputation. 26 of the remaining 27 patients maintained walking ability, 23 of those without assistive devices. Walking ability was independent from the presence of osteomyelitis at the time of reconstruction and from the presence of fusion. CONCLUSION: Foot reconstruction with an Ilizarov ring fixator led to limb salvage in 93%. The vast majority (96.3%) of patients with successful limb salvage was ambulatory, independent from radiologic fusion, and presence of osteomyelitis at the time of reconstruction. These findings encourage limb salvage and deformity correction in this difficult-to-treat disease, even with underlying osteomyelitis.

Accuracy of three dimensional-planned patient-specific instrumentation in femoral and tibial rotational osteotomy for patellofemoral instability.

PURPOSE: Patellofemoral instability can be caused by tibial or femoral torsional deformity. Established surgical treatment options are rotational osteotomies, but the transfer from pre-operative planning to surgical execution can be challenging. Patient-specific instruments (PSI) are proofed to be helpful tools in realignment surgery. However, accuracy of PSI in femoral and tibial rotational osteotomies remains still unknown. Goal of the present study was to evaluate the accuracy of PSI in femoral and tibial rotational osteotomies in a patient population suffering from patellofemoral instability. METHODS: All patients that underwent femoral or tibial rotational osteotomy using PSI in case of patellofemoral instability from October 2015 until April 2019 in our clinic were included. Twelve knees with twelve supracondylar femoral and seven supratuberositary tibial rotational osteotomies could be included. Accuracy of the correction was assessed using pre- and post-operative CT scans based on conventional measurements and, in 3D, based on 3D bone models of the respective patients. RESULTS: CT measurements revealed an absolute difference between planned and achieved rotation of 4.8° ± 3.1° for femoral and 7.9° ± 3.7° for tibial rotational osteotomies without significant difference (p = 0.069). Regarding 3D assessment, a significant difference could be observed for the residual error between femoral and tibial rotational osteotomies in the 3D angle (p = 0.014) with a higher accuracy for the femoral side. CONCLUSION: The application of PSI for femoral and tibial rotational osteotomy is a safe surgical treatment option. Accuracy for femoral rotational osteotomies is higher compared with tibial rotational osteotomies using PSI.

The accuracy of joint aspiration for the diagnosis of shoulder infections.

BACKGROUND: Shoulder joint aspirations are frequently performed to rule out infection. In case of unsuccessful aspiration, physicians often augment the aspiration liquid by injecting saline solution. METHODS: We performed shoulder joint aspirations by fluoroscopic assistance and analyzed the value of an additional saline solution irrigation in patients undergoing revision shoulder surgery. Native joints and post-fracture repair, post-arthroscopy, and post-arthroplasty shoulders were included. A minimum of 3 deep intraoperative tissue samples served as the microbiological gold standard. RESULTS: We performed 106 aspirations occurring between 0 and 179 days before revision surgery. Among them, we could sample intra-articular liquid directly in 60 cases and after saline solution injection in 43 cases, whereas 3 cases remained unsuccessful. According to intraoperative samples, 24 shoulders were infected but only 10 of 24 (42%) yielded pathogens in the aspirate. Moreover, of the 43 saline solution-enforced irrigations, none revealed bacteria but 8 (17%) confirmed infection in intraoperative samples. Overall, the sensitivity, specificity, positive predictive value, and negative predictive value of presurgical aspirations were 33%, 98%, 80%, and 83%, respectively. CONCLUSION: When surgical revision is planned, presurgical shoulder joint aspiration is not reliable to sufficiently exclude shoulder joint infection. Nevertheless, a positive aspiration finding can guide clinical decision making, so we propose to perform aspiration only if there is a clinically high index of suspicion for an infection. Irrigation after unsuccessful primary aspiration is futile.

Rotation or flexion alters mechanical leg axis measurements comparably in patients with different coronal alignment.

PURPOSE: Flexion and rotation of the knee joint are supposed to alter the measurement of the mechanical leg axis on long leg radiographs. However, in patients with varus or valgus alignment it has not been systematically analyzed so far. The hypothesis is that measurement of the mechanical leg axis is more influenced by flexion and rotation in presence of varus or valgus alignment compared to patients with a straight coronal alignment. METHODS: 3D surface models of the lower extremities of seven individuals with varying degrees of coronal alignment were created based on CT data. The coronal alignment of the seven individuals captured the range between 9° varus and 9° valgus with equal steps of 3°. Combinations of internal and external rotations of 10°, 20°, and 30° with flexion of 5°, 10°, 15°, 20°, and 30° were simulated. The mechanical leg axis was measured for each combination as the antero-posterior (ap)-projected hip-knee-ankle (HKA-) angle. RESULTS: 294 simulations with all combinations of rotation and flexion were performed. Ranges of deviation of HKA never showed a critical deviation of more than 3° from median values. Deviations from baseline appeared normally distributed for all flexion and rotation combinations (p < 0.05) and the probability for a deviation from the mean mechanical leg axis of more than 3° was less than 0.03 for all combinations. Comparability of the models, therefore, could be assumed. CONCLUSION: Deviations in HKA-angle measurements, caused by rotation or flexion, does not vary relevantly through the range of coronal alignment of 9° varus to 9° valgus. As a clinical relevance, deviations in HKA-angle measurements can be considered as comparable in patients with different coronal alignment. LEVEL OF EVIDENCE: III.

Introducing the Lateral Femoral Condyle Index as a Risk Factor for Anterior Cruciate Ligament Injury.

BACKGROUND: The asymmetry of the medial and lateral knee compartments contributes significantly to femorotibial biomechanics and pivoting, and it is reported to be a relevant risk factor for an anterior cruciate ligament (ACL) injury. PURPOSE: (1) To assess the role of femoral condyle sphericity as a risk factor for an ACL rupture and rerupture. (2) To compare the new risk factor with existing bony morphological risk factors via magnetic resonance imaging (MRI) and to assess the most predictive risk factor for an ACL rupture. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective case-control study of 60 patients was conducted. Three age- and sex-matched cohorts (each n = 20) were analyzed: ACL reruptures, primary ACL ruptures, and a control group consisting of isolated meniscal tears or patients with anterior knee pain without signs of trochlear dysplasia. The lateral femoral condyle index (LFCI) as a novel MRI measurement was developed to quantify femoral sphericity. In addition, previously known MRI risk factors associated with ACL injury were analyzed (notch width index, medial tibial slope, lateral tibial slope, medial tibial depth, and lateral tibial height). Differences among groups were compared; cutoff values were defined; and diagnostic performance of the risk factors was assessed. The risk factors were subsequently analyzed with multiple logistic regression. RESULTS: The LFCI was significantly smaller in knees with ACL reruptures (median, 0.67; range, 0.59-0.75) and primary ACL ruptures (0.67; range, 0.60-0.75) than in the control group (0.76; range, 0.6-0.81; P < .01). The LFCI yielded the highest area under the curve among the analyzed risk factors: 0.82 (95% CI, 0.7-0.9). A cutoff of 0.70 yielded a sensitivity of 78% and a specificity of 80% to predict an ACL rupture or rerupture (odds ratio, 13.79; 95% CI, 3.67-51.75). In combination with lateral tibial height (cutoff, 3.8 mm) and lateral tibial slope (cutoff, 2.9°), the diagnostic performance was improved. The area under the curve was 0.86 (95% CI, 0.75-0.94), with a sensitivity of 90% and a specificity of 70% (odds ratio, 21.00; 95% CI, 5.10-85.80). CONCLUSION: A decreased LFCI is associated with an ACL injury. The LFCI, lateral tibial height, and lateral tibial slope are the most predictive risk factors for an ACL injury. These findings might aid clinicians in identifying patients at risk for an ACL injury and inform the patient after reconstruction for a higher risk of rerupture.

Uncemented Total Hip Arthroplasty Through the Direct Anterior Approach: Analysis of a Consecutive Series of 275 Hips With a Minimum Follow-Up of 10 Years.

BACKGROUND: The purpose of this study was to document complications, outcomes, and 10-year survivorship of primary total hip arthroplasty (THA) using a direct anterior approach with an uncemented, straight, hydroxyapatite-coated stem and an uncemented cup. METHODS: A retrospective, consecutive series of 275 primary THAs through a direct anterior approach with traction table using Medacta Versafit cup and Quadra-H stem with a minimum of 10-year follow-up was identified. The cumulative 10-year survival of the implants was estimated using Kaplan-Meier estimator. All complications, reoperations, and failures were analyzed. Subjective and clinical outcomes (Subjective Hip Value, Western Ontario and McMaster Universities Osteoarthritis Index, and Harris Hip Score) were measured. RESULTS: Of 256 patients (275 hips, 143 men and 113 women) with a mean age of 63 (range, 24-85) years, 48 (19%) patients (52 hips) deceased not related to the surgery after a mean time 49 months (range, 3-118) postoperatively. At >10-year follow-up, 9 THAs were revised. The overall implant survival rate was 96.8% (95% confidence interval, 94.4-98.7) at 10 years. One cup and 1 stem were revised because of aseptic loosening. At the last follow-up, the median Subjective Hip Value was 90% (range, 20-100), the Western Ontario and McMaster Universities Osteoarthritis Index score reached a median of 0.2 points (range, 0-6.3), and the median Harris Hip Score points was 99 (range, 29-100). CONCLUSION: Primary THA through an anterior minimal invasive approach with the mentioned implants showed low revision rates and good to excellent clinical outcome after at least 10 years.

Can Genipin-coated Sutures Deliver a Collagen Crosslinking Agent to Improve Suture Pullout in Degenerated Tendon? An Ex Vivo Animal Study.

BACKGROUND: The suture-tendon interface is often the weakest link in tendon-to-tendon or tendon-to-bone repair. Genipin is an exogenous collagen crosslink agent derived from the gardenia fruit that can enhance suture force to failure of the tendon-suture interface. Viable methods for intraoperative clinical delivery of genipin could be of clinical utility, but to our knowledge have not yet been extensively studied. QUESTIONS/PURPOSES: The purposes of this study were (1) to evaluate whether sutures precoated with genipin can augment the suture-tendon interface to improve force to failure, stiffness, and work to failure in healthy and degenerated tendons; and (2) to determine the effect of genipin on the extent and distribution of crosslinking. METHODS: Single-stitch suture pullout tests were performed ex vivo on 25 bovine superficial digital flexor tendons. To assess effects on native tissue, one group of 12 tendons was cut in proximal and distal halves and randomized to treatment (n = 12) and control groups (n = 12) in a matched-pair design. One simple stitch with a loop with either a normal suture or genipin-coated suture was applied to tendons in both groups. To simulate a degenerative tendon condition, a second group of 13 tendons was cut in proximal and distal halves, injected with 0.2 mL of collagenase D (8 mg/mL) and incubated for 24 hours before suturing with either a genipin-coated suture (n = 13) or their matched controls (n = 13). Sutures from all groups then were loaded to failure on a universal materials testing machine 24 hours after suturing. Suture pullout force, stiffness, and work to failure were calculated from force-displacement data and compared between the groups. Additionally, fluorescence was measured to determine the degree of crosslinking quantitatively and a qualitative analysis of the distribution pattern was performed by microscopy. RESULTS: In healthy tendon pairs, the median maximum pullout force was greater with genipin-coated sutures than with control sutures (median, 42 N [range, 24-73 N] versus 29 N [range, 13-48 N]; difference of medians, 13 N; p = 0.003) with corresponding increases in the required work to failure (median, 275 mJ [range, 48-369 mJ] versus 148 mJ [range, 83-369 mJ]; difference of medians, 127 mJ; p = 0.025) but not stiffness (median, 4.1 N/mm [range, 2.3-8.1 N/mm] versus 3.3 N/mm [range, 1.1-9.6 N/mm]; difference of medians, 0.8 N/mm; p = 0.052). In degenerated tendons, median maximum pullout force was greater with genipin-coated sutures than with control sutures (median, 16 N [range, 9-36 N] versus 13 N [range, 5-28 N]; difference of medians, 3 N; p = 0.034) with no differences in work to failure (median, 75 mJ [range, 11-249 mJ] versus 53 mJ [range, 14-143 mJ]; difference of medians, 22 mJ; p = 0.636) or stiffness (median, 1.9 N/mm [range, 0.7-13.4 N/mm] versus 1.6 N/mm [range, 0.5-5.6 N/mm]; difference of medians, 0.3 N/mm; p = 0.285). Fluorescence was higher in tendons treated with genipin-coated sutures compared with the control group, whereas higher fluorescence was observed in the treated healthy compared with the degenerated tendons (difference of means -3.16; standard error 1.08; 95% confidence interval [CI], 0.97-5.34; p = 0.006/healthy genipin: mean 13.04; standard error 0.78; 95% CI, 11.47-14.62; p < 0.001/degenerated genipin: mean 9.88; SD 0.75; 95% CI, 8.34-11.40; p < 0.001). CONCLUSIONS: Genipin-coated sutures improved force to failure of a simple stitch at the tendon-suture interface in healthy and degenerated tendons in an ex vivo animal model. Fluorescence was higher in tendons treated with genipin-coated sutures compared with the control group. CLINICAL RELEVANCE: A genipin-coated suture represents a potential delivery vehicle for exogenous crosslink agents to augment suture retention properties. In vivo animal studies are the next logical step to assess safety and efficacy of the approach.