Long-term clinical and radiological outcome in patients with severe Legg-Calvé-Perthes disease after Chiari pelvic osteotomy: a mean of 14 years follow-up.

INTRODUCTION: The Chiari pelvic osteotomy (CPO) has been recommended as a salvage procedure to improve head coverage in case of hip joint incongruence in paediatric hip disease. In this study, we aimed to assess the long-term results of CPO for severe Legg-Calvé-Perthes disease (LCPD). METHODS: A total of 39 patients who underwent a CPO at our department between 1995 and 2010 were prospectively followed both radiologically (Stulberg classification) and clinically (Harris Hip Score [HHS], conversion into total hip arthroplasty). In this study, we retrospectively reviewed the cases of 12 hips (12 patients, 3 girls, 8 left hips) treated by CPO for severe LCPD (Catterall grade 3 or 4) with hip joint incongruence. Mean follow-up was 14.0 (range 7.6-21.3) years. RESULTS: Mean age at surgery was 10.2 (range 8.2-17.8) years. Additional femoral osteotomy was performed in 8 patients. A good radiological result (Stulberg I or II) was achieved in 2 patients, a fair result (Stulberg III) in 4 patients, and a poor outcome (Stulberg IV or V) in 6 patients. Mean postoperative HHS averaged 93 (range 65-100) points. An excellent functional outcome (HHS 90-100 points) was achieved in 9 patients. No patient underwent total hip arthroplasty during follow-up. Postoperative limb-length discrepancy was found in 3 patients. CONCLUSIONS: CPO for severe LCPD with hip joint incongruence resulted in good long-term clinical outcome in about ⅔ of our patients after a mean of 14 years. Our results suggest that CPO can still be considered as a salvage joint-conserving procedure in this selected group of younger patients.

Correction of adolescent idiopathic scoliosis using a convex pedicle screw technique with low implant density.

AIMS: The aim of this retrospective study was to compare the correction achieved using a convex pedicle screw technique and a low implant density achieved using periapical concave-sided screws and a high implant density. We hypothesized that there would be no difference in outcome between the two techniques. METHODS: We retrospectively analyzed a series of 51 patients with a thoracic adolescent idiopathic scoliosis. There were 26 patients in the convex pedicle screw group who had screws implanted periapically (Group 2) and a control group of 25 patients with bilateral pedicle screws (Group 1). The patients' charts were reviewed and pre- and postoperative radiographs evaluated. Postoperative patient-reported outcome measures (PROMs) were recorded. RESULTS: The number of implants (14.5 vs 17.1) and the implant density (1.5 vs 1.9) were significantly lower in Group 2 (p < 0.001). Operating time was 27 minutes shorter in Group 2 than in Group 1, with a mean of 217 minutes (SD 50.5; 120 to 346). The duration of surgery per instrumented vertebra was reduced by 19% in Group 2 (p = 0.011). No statistical difference was found in the postoperative Cobb angle, vertebral rotation, the relative correction achieved, or postoperative PROMs. CONCLUSION: Despite a lower implant density and achieving correction through a convex rod, surgical correction of the Cobb angle and vertebral body rotation was similar in both groups. Periapical pedicle screws and primary correction on the concave side do not seem to be mandatory in order to achieve good surgical results in idiopathic thoracic scoliosis. The operating time was shorter in the group with lower implant density. In conclusion, the technique provided good results and has the potential to reduce complications and costs. Cite this article: Bone Joint J 2021;103-B(3):536-541.

Linear Anterior-Posterior Computed Tomography Parameters Used to Quantify Trochlear Dysplasia Are More Reliable Than Angular Measurements.

PURPOSE: (1) To evaluate the reliability of 9 commonly used quantitative parameters of the trochlear morphology on computed tomography (CT) and (2) to analyze for differences in the reliability regarding patient subgroups (patellofemoral instability [PFI] vs non-PFI). METHODS: A retrospective analysis of lower-limb CT scans performed between August 1996 and February 2013 was performed. The CT scans of all patients with PFI and 30 randomly selected cases without a history of PFI (non-PFI) were included. The following measurements were performed on 1 proximal axial CT slice at the entrance of the trochlear groove and 1 slice 5 mm further distal: relative medial, central, and lateral trochlear height; trochlear depth; relative transverse trochlear shift; trochlear facet asymmetry; sulcus angle; and medial and lateral trochlear slope. Four investigators performed the measurements independently, and intraclass correlation coefficients (ICCs) were calculated for the entire study group, as well as for the PFI and non-PFI groups separately. RESULTS: In total, 66 cases (36 PFI cases) were included in the study. We found almost perfect inter-rater and intrarater agreement for the trochlear height on both axial CT slices (ICC, 0.831-0.977). For the other measurements, we found only fair reliability (ICC < 0.4) on the proximal CT slice, whereas on the distal CT slice, at least moderate reliability (ICC > 0.4) was observed. ICCs were lower for many parameters in the PFI group. Angular values were less reliable than linear values. In particular, measurements involving the medial facet (i.e., sulcus angle, medial trochlear slope, and trochlear facet asymmetry) were less reliable. CONCLUSIONS: When interpreting quantitative parameters defining the trochlear morphology, one must taken into account the considerably lower reliability of angular parameters such as the commonly used sulcus angle compared with linear measurements. Radiologic measurements are less reliable in cases of PFI than in subjects without instability. LEVEL OF EVIDENCE: Level III, retrospective case-control study.

Increased Staphylococcus aureus Biofilm Formation on Biodegradable Poly(3-Hydroxybutyrate)-Implants Compared with Conventional Orthopedic Implants: An In Vitro Analysis.

OBJECTIVE: To compare the biofilm formation on a biodegradable material, poly(3-hydroxybutyrate) (PHB), with that on conventional titanium (Ti) and steel (St) implant material. METHODS: Pins made of the different materials were incubated in Müller-Hinton broth inoculated with 2 × 10 colony-forming units (CFU)·mL of Staphylococcus aureus for 2 and 7 days and then sonicated for the disruption of the biofilms. CFU were counted to quantify the number of bacteria in the biofilm, and the cell proliferation assay 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H- tetrazolium-5-carboxanilid salt was used to evaluate their metabolic activity. Scanning electron microscopy visualized the structure of the biofilm. RESULTS: We found a significantly higher metabolic activity and CFU count in the biofilm of PHB pins compared with St and Ti pins (analysis of variance, P < 0.0001). Scanning electron microscopy revealed structured biofilms on PHB pins already after 2 days of incubation, which was not observed on the other tested implants. CONCLUSION: PHB implants seem to provide an environment that advantages the formation of biofilms of S. aureus, a common pathogen in implant-related infections. The amount of biofilm is higher on PHB implant compared with conventionally used orthopedic titanium and steel implants. To overcome the potential risk of surgical site infections linked to the clinical use of PHB implants, possible modifications of the material, increasing its antibacterial properties, need to be further investigated.

Patella Height Correlates With Trochlear Dysplasia: A Computed Tomography Image Analysis.

PURPOSE: The aim of this study was to investigate the position of the patella relative to the trochlea for a possible correlation with radiologic parameters characterizing the form of the trochlea. METHODS: The computed tomography scans of 36 cases with patellofemoral instability and 30 without (mean age, 24.7 ± 6.8 years) were studied. The height of the patella relative to the trochlea was evaluated as the distance between the axial slice where the patella (P) showed its widest diameter, as the patella at this level has the greatest potential to form the trochlea, and the proximal entrance of the femoral trochlea (TE). The correlations between this parameter and several radiologic parameters used to evaluate trochlear dysplasia, including trochlea height, transverse trochlea shift, trochlea depth, sulcus angle, lateral and medial trochlea slope, trochlea facet asymmetry, and the Dejour trochlea type, were calculated. RESULTS: The P-TE distance correlated significantly with all trochlea parameters evaluated, with a more dysplastic trochlea in cases of higher position of the patella: medial, central, and lateral trochlea height (0.287

Segmental torsion assessment is a reliable method for in-depth analysis of femoral alignment in Computer Tomography.

PURPOSE: De-rotational osteotomies are indicated in patients with pathologic femoral torsion. However, there is disagreement whether an osteotomy should be performed proximally or distally. Conventionally only the total torsion is measured, which does not allow differentiation between a torsional deformity located in the proximal or distal metaphysis or the diaphysis. The aim of this study is to validate a new multi-level measurement protocol for evaluation of the magnitude of torsion of the respective femoral segments in CT. PATIENTS AND METHODS: The torsional profile of 30 femora was evaluated in CT scans. For separate measurements of the torsion of the metaphysis and the diaphysis, four axes where determined: one through the femoral neck, a second determined by the midpoint of the femoral shaft and the lesser trochanter, a third determined by a tangent dorsal to the popliteal surface, and a fourth axis posterior to the condyles. The total femoral torsion was measured between the first and the fourth axis, proximal torsion between the first and the second, mid torsion between the second and the third, and distal torsion between the third and the fourth axis. Four investigators performed all measurements independently and intra-class correlation coefficients (ICC) were calculated to evaluate intra- and inter-rater reliability. RESULTS: Average total femoral torsion was 22.6 ± 8.7°, proximal torsion 47.7 ± 10.6°, mid torsion -33.4 ± 9.9°, and distal torsion 8.3 ± 3.2°. Intra-rater ICC ranged between 0.504 and 0.957 and inter-rater ICC between 0.643 and 0.992. The majority of the ICC were graded as "almost perfect" and some as "substantial" agreement. CONCLUSION: Evaluation of the segmental torsion of the femur allows in-depth analysis of femoral alignment. High reliability was shown for this measuring method in computed tomography, which can be deployed when studying interdependencies between joint pathologies and torsional deformities or when planning the site for an osteotomy. LEVEL OF EVIDENCE: Level III.

The use of tibial tuberosity-trochlear groove indices based on joint size in lower limb evaluation.

PURPOSE: The correlation between tibial tuberosity-trochlear groove distance (TT-TG) and joint size, taking into account several different parameters of knee joint size as well as lower limb dimensions, is evaluated in order to assess whether TT-TG indices should be used in instead of absolute TT-TG values. METHODS: This study comprised a retrospective analysis of knee CT scans, including 36 cases with patellofemoral instability (PFI) and 30 controls. Besides TT-TG, five measures of knee joint size were evaluated in axial CT slices: medio-lateral femur width, antero-posterior lateral condylar height, medio-lateral width of the tibia, width of the patella and the proximal-distal joint size (TT-TE). Furthermore, the length of the femur, the tibia and the total leg length were measured in the CT scanogram. Correlation analysis of TT-TG and the other parameters was done by calculating the Spearman correlation coefficient. RESULTS: In the PFI group lateral condylar height (r = 0.370), tibia width (r = 0.406) and patella width (r = 0.366) showed significant moderate correlations (p < 0.03) with TT-TG. Furthermore, we found a significant correlation between TT-TG and tibia length (r = 0.371) and total leg length (r = 381). The control group showed no significant correlation between TT-TG and knee joint size or between TT-TG and measures of lower limb length. CONCLUSIONS: Tibial tuberosity-trochlear groove distance correlates with several parameters of knee joint size and leg length in patients with patellofemoral instability. Application of indices determining TT-TG as a ratio of joint size could be helpful in establishing the indication for medial transfer of the tibial tuberosity in patients with PFI. LEVEL OF EVIDENCE: Level III.

Patient-reported outcome of surgical treatment for lumbar spinal epidural lipomatosis.

BACKGROUND CONTEXT: Spinal epidural lipomatosis (SEL) is a rare condition characterized by an excessive accumulation of fat tissue in the spinal canal that can have a compressive effect, leading to clinical symptoms. This condition has a distinct pathology from spinal stenosis associated with degeneration of the intervertebral discs, ligaments, and facet joints. Several different conservative and surgical treatment strategies have been proposed for SEL, but its treatment remains controversial. There is a lack of evidence documenting the success of surgical decompression in SEL, and no previous studies have reported the postoperative outcome from the patient's perspective. PURPOSE: The aim of the present study was to evaluate patient-rated outcome after surgical decompression in SEL. STUDY DESIGN: A retrospective analysis of prospectively collected data was carried out. PATIENT SAMPLE: A total of 22 patients (19 males; age: 68.2±9.9 years) who had undergone spine surgery for SEL were identified from our local Spine Surgery Outcomes Database, which includes a total of 10,028 spine surgeries recorded between 2005 and 2012. Inclusion criteria were epidural lipomatosis confirmed by preoperative magnetic resonance imaging (MRI) scans and subsequent decompression surgery without spinal fusion. OUTCOME MEASURES: The Core Outcome Measures Index (COMI) was used to assess patient-rated outcome. The COMI includes the domains pain (separate 0-10 scales for back and leg pain), back-specific function, symptom-specific well-being, general quality of life (QOL), work disability, and social disability. METHODS: The questionnaires were completed preoperatively and at 3, 12, and 24 months postoperatively. Surgical data were retrieved from the patient charts and from our local Spine Surgery Outcomes Database, which we operate in connection with the International Spine Tango Registry. Differences between pre- and postoperative scores were analyzed using paired t tests and repeated measures analysis of variance. RESULTS: At 3-months follow-up, the COMI score and scores for leg pain and back pain had improved significantly compared with their preoperative values (p<.005). The mean decrease in COMI score after 3 months was 2.6±2.4 (range: -1.3 to 6.5) points: from 7.5±1.7 (range: 3.5-10) to 4.9±2.5 (range: 0.5-9.6). A total of 11 patients (50%) had an improvement of the COMI of more than the minimal clinically important change (MCIC) score of 2.2 points. The mean decrease in leg pain after 3 months was 2.4±3.5 (-5 to 10) points. Overall, 17 patients (77.3%) reported a reduced leg pain, 12 (54.6%) of whom by at least the MCIC score of 2 points. The significant reductions from baseline in COMI and leg and back pain scores were retained up to 2 years postoperatively (p<.02). The general QOL item of the COMI improved significantly after surgery (p<.0001). Over 80% of the cohort rated their preoperative QOL as bad (n=13) or very bad (n=5), whereas 3 months after surgery, only 7 patients rated their QOL as bad, and one as very bad (36%). CONCLUSIONS: The present study is the first to demonstrate that surgical decompression is associated with a statistically significant improvement in patient-rated outcome scores in patients with symptomatic SEL, with a clinically relevant change occurring in approximately half of them. Surgical decompression hence represents a reasonable treatment option for SEL, although the reason behind the less good response in some patients needs further investigation.

High Femoral Anteversion Is Related to Femoral Trochlea Dysplasia.

PURPOSE: To investigate the possible relation between femoral anteversion (AV) and trochlear morphology. METHODS: Among 560 available lower-limb computed tomography (CT) scans, those with previous fracture, arthroplasty, or osteotomy were excluded and 40 cases were randomly selected. The following 4 lines were determined from the CT scans: 1 through the center of the femoral head and neck; 1 through the lesser trochanter and the center of the femoral shaft; 1 as a tangent to the dorsal part of the distal femur, just above the gastrocnemius insertion; and 1 as a tangent to the posterior condyles. Between the respective lines, the following parameters of femoral AV were determined: (1) total AV, (2) proximal AV, (3) diaphyseal AV, and (4) distal AV. Trochlea parameters were determined from 2 separate axial CT slices (proximal trochlea and 5 mm farther distally): trochlea height (medial, central, lateral), transverse trochlea shift, trochlea depth, sulcus angle, lateral trochlea slope, and Dejour trochlea type. To prove or disprove our study hypothesis, a correlation analysis was performed between the variables of AV and trochlear morphology. RESULTS: The total AV was significantly correlated with the trochlea parameters trochlea depth (P = .032), sulcus angle (P = .05), and lateral trochlea slope (P = .001). The diaphyseal AV was significantly correlated with the sulcus angle (P = .009). The distal AV showed significant correlations with medial, central, and lateral trochlea height (.005

Treatment for ischial tuberosity avulsion fractures in adolescent athletes.

PURPOSE: Avulsion fractures of the ischial tuberosity are rare sports injuries typically occurring in young athletes. Their misdiagnosis may lead to chronic pain or disability. The aim of this study is to report a retrospective series of patients sustaining a fracture of the ischial tuberosity and to propose decision guidelines. METHODS: The mechanism of accident, the diagnostic management, the mode of treatment and outcome after avulsion fractures of the ischial tuberosity in adolescents were analysed. RESULTS: Thirteen patients (1 female and 12 males) with a median age of 15 years (range 13-16 years) with an avulsion fracture of the ischial tuberosity were included. Twelve of these patients suffered from sports injuries leading to the avulsion fracture. Five of our patients with a displacement of >15 mm were treated operatively. The outcome was excellent in cases of acute presentation and osteosynthesis. Eight patients were treated conservatively: four of them showed a displacement of <15 mm and had an excellent outcome; and the other four patients had a displacement of >15 mm. Two of those patients had excellent outcome with regular bone healing, the remaining two patients developed pseudarthrosis associated with a good outcome. CONCLUSION: The present paper shows that in patients with displacement of <15 mm, conservative treatment yields excellent results and early operative intervention should be considered in physically active patients with displacement of >15 mm.

Antegrade nailing can prevent cubitus varus and valgus after pediatric supracondylar fractures with impacted columns.

Supracondylar fractures are commonly encountered in the pediatric population. An impacted radial or ulnar column may result in the deviation of the elbow axis in the frontal plane clinically seen as cubitus varus or valgus. Antegrade nailing has become a feasible alternative to treat supracondylar fractures. It is not known whether it can prevent the development of cubitus varus or valgus in the cases of fractures with impacted columns. Between 1994 and 2009, 264 supracondylar humeral fractures were treated. Nineteen patients presented with either an impacted ulnar (n = 12) or radial (n = 7) column and were included in the study. The average elbow angle in fractures with impacted radial column was 159° mean (range 153-167°) compared with 179° (range 173-184°) in fractures with an impacted ulnar column. After closed reduction and antegrade nailing, the elbow angle was restored to normal values. At follow-up examination after a mean of 3.8 years (range 2.4-7.6 years), no further changes of the humeral-ulnar angle were seen. We are able to show that antegrade nailing is a safe method to treat supracondylar humeral fractures with impacted columns.

Reconstruction of the sternoclavicular joint in active patients with the figure-of-eight technique using hamstrings.

BACKGROUND: Dislocations of the sternoclavicular joint are rare injuries caused by massive forces applied to the joint. A high rate of complications has been reported following this injury emphasizing the importance of an accurate diagnosis and therapy. METHODS: We report a series of patients with chronic anterior or posterior sternoclavicular instability treated with figure-of-eight gracilis- or semitendinosus-tendon reconstruction. Tendon grafts were collected from the patient's ipsilateral knee. Preoperative and postoperative DASH scores were compared to evaluate the outcome. RESULTS: Six patients (mean age, 22 years; range 15-46; male = 3; female = 3) were included. The patients sustained an isolated dislocation of the sternoclavicular joint resulting from a high-energy trauma. Anterior instability was observed in 3 patients, posterior instability in 2 patients and the remaining patient showed multidirectional instability. The mean time from injury to operation was 8 months (range, 4-33). The semitendinosus tendon was used in 4 patients, the gracilis tendon in 2 patients, respectively. Follow-up examination was after 22 months (range, 14-34). The DASH score improved from 54.3 points (range, 45.7-68.8) preoperatively to 28.8 points (range, 25.8-34.5) postoperatively. All patients returned to full activity without limitations including competitive contact sports. CONCLUSION: Stabilization of the sternoclavicular joint with the figure-of-eight technique seems to be a feasible alternative for young and active patients with remaining instability following conservative treatment.

The acute compartment syndrome following fractures of the lower leg in children.

INTRODUCTION: The acute compartment syndrome (ACS) of the lower leg is a rare but serious complication following either fractures or soft tissue injuries. An acute intervention consisting of fasciotomy is indicated as ACS may cause muscle and nerve damage. The aim of the present study was to evaluate the cause, the incidence, the time to fasciotomy and the outcome of ACS of the lower leg following fractures in a paediatric population. PATIENTS AND METHODS: A retrospective analysis of all patients with ACS following a fracture of the lower leg treated from 1998 to 2010 was performed. The time from admission to occurrence of the ACS, the kind of fracture and surgical treatment was evaluated. Accident mechanisms were recorded. RESULTS: A total of 1028 fractures of the lower leg were treated. 31 patients (3%) with a median age of 14.6 years (range 7.3-17.1 years) developed an ACS. In the group of patients younger than 12 years the incidence was even lower (1.3%). 81% of injuries leading to ACS were caused by high-energy trauma, with motorcycle accidents being the most common (45%). External fixation was used in 45%, including all open fractures. The diagnosis of an ACS was primarily based on clinical symptoms. In 23 cases an intracompartmental pressure of median 55mmHg (range 40-100mmHg) were measured. ACS was diagnosed after 19h mean (range: 1.5-65h). There was a tendency that the ACS occurred earlier after high-energy trauma than after low energy trauma (mean 16.9 vs. mean 28h). No complications linked to the compartment syndrome were observed. DISCUSSION: ACS can occur up to 65h after an accident and therefore clinical monitoring is fundamental in order to be able to surgically intervene as soon as possible when needed. With early decompression complications can be prevented.

Post-traumatic coxa vara in children following screw fixation of the femoral neck.

BACKGROUND AND PURPOSE: The rare displaced fractures of the femoral neck in children need accurate reduction and rigid fixation. The implants commonly used for internal fixation in children are pins or screws. We evaluated the long-term outcome in children who sustained fractures of the proximal femur that were treated by screw fixation. PATIENTS AND METHODS: All 22 children (mean age 12 (5-16) years) with fractures of the femoral neck that were treated with screw fixation (mean 2.4 (1-3) screws) at our department between 1990 and 2006 were evaluated. For measurement of outcome, the Harris hip score (HHS) was used and the development of post-traumatic coxa vara was assessed from the difference in the neck-shaft angle postoperatively and at the latest follow-up examination, after mean 4 (2-15) years. RESULTS: A loss of reduction was observed in 12 patients. There was a statistically significant correlation between the HHS and the changes in the neck-shaft angle. INTERPRETATION: Loss of reduction was found in more than half of the children. Screw fixation cannot be recommended for the treatment of femoral neck fractures in children due to a substantial number of post-traumatic coxa vara.