Thumb Metacarpophalangeal Joint Kinematics and Elongation of the Ulnar Collateral Ligament.

PURPOSE: The purpose of the study was to determine if the sphericity of the thumb metacarpophalangeal (MCP) joint influences the joint's rotational axis (RA) and elongation patterns of the ulnar collateral ligament (UCL). METHODS: Ulnar collateral ligament origins and attachments of 28 fresh-frozen cadaveric thumbs were marked with a radiopaque marker. Lateral radiographs were obtained in neutral and 20°, 40°, and 60° of flexion. The dorsal and palmar joint gap and the length of four different UCL portions were digitally measured in all flexion states. The RA was determined by the intersection of the midshaft axis of the proximal phalanx in neutral and flexion states. Sphericity of the MCP joint was assessed using morphometric parameters. Joints were grouped as round or flat. Differences in all measured parameters between groups were analyzed. RESULTS: During flexion, the dorsal joint gap increased by 322% in flat joints and 163% in round joints. The palmar joint gap decreased to 45% in flat joints and to 87% in round joints. The RA was at 29% of metacarpal height and 96% of metacarpal length in flat joints and at 40% of height and 86% of length in round joints. Maximum UCL elongation (111%) was noted at 40° flexion in the dorsal proper UCL in flat joints and at 60° flexion in the accessory UCL (117%) in round joints. CONCLUSIONS: In flat MCP joints, the RA is more dorsal and distal in the metacarpal head compared to round joints, resulting in a hinged flexion motion. Elongation of the UCL is highest at end flexion in round joints and highest at midflexion in flat joints. CLINICAL RELEVANCE: The different kinematics of flat and round MCP joints may contribute to the understanding of the pathophysiology of UCL ruptures. The propensity of this injury and the position in which they occur may be affected by the MCP joint morphology.

An isoelastic monoblock cup versus a modular metal-back cup: a matched-pair analysis of clinical and radiological results using Einzel-Bild-Röntgen-Analyse software.

INTRODUCTION: Bone preservation and long-term survival are the main challenges in cementless total hip arthroplasty (THA). A good bone stock is especially important for adequate anchorage of the cup in revision cases. However, the optimal acetabular cup design for preserving good bone stock is still unclear. We aimed to compare clinical outcome, radiological alterations, migration, and wear at mid-term for two different cup types. MATERIALS AND METHODS: This retrospective matched-pair study was performed using the data for 98 THA cases treated with a monoblock cup composed of vitamin E-blended highly cross-linked polyethylene (VEPE; monoblock group) or a modular cup composed of a highly cross-linked polyethylene (HXLPE) without an antioxidant (modular group). Clinical results were evaluated using the Harris Hip Score (HHS). The obtained radiographs were analyzed for radiological alterations, migration, and wear using Einzel-Bild-Röntgen-Analyse (EBRA) software. RESULTS: The mean follow-up duration was 73.2 ± 19.2 months (range: 32-108 months) and 60.5 ± 12.2 months (range: 20-84 months) in the monoblock and modular groups, respectively. HHS improved to 95.7 points in the monoblock group and 97.6 points in the modular group, without significant differences (p = 0.425). EBRA measurements were obtained in all cases. Acetabular bone alterations were not detected on radiological assessments. Mean cup migration was 1.67 ± 0.92 mm (range: 0.46-3.94 mm) and 1.24 ± 0.87 mm (range: 0.22-3.62 mm) in the monoblock and modular groups. The mean wear rate was 0.21 ± 0.18 mm (range: 0.00-0.70 mm) and 0.20 ± 0.13 mm (range: 0.00-0.50 mm) in the monoblock and modular groups. Both migration and wear pattern showed no significant differences (p = 0.741 and 0.243). None of the cases required revision surgery, yielding an implant survival rate of 100% in both groups. CONCLUSION: The isoelastic press-fit monoblock VEPE cup and modular metal-back HXLPE cup showed equivalent mid-term wear and cup migration. Long-term studies are required to determine the effects of modularity, isoelasticity, and polyethylene stabilization with vitamin E on cup loosening and survival rates.

Downsizing in total hip arthroplasty. A short stem as a revision implant.

BACKGROUND: Short stems have constantly gained popularity in primary total hip arthroplasty (THA) over the last decade. Although cementless short stems are not primarily designed to be used as revision implants, there may be certain indications for which downsizing the femoral component in failed conventional THA is potentially advantageous. METHODS: In this single center retrospective case series, six patients who underwent revision using a calcar-guided short stem after failed THA are presented. The mean follow-up was 3.32 years (SD 0.63 years). The health status was evaluated by the EQ-5D-5L score. Patient reported outcome measurements (PROM) were recorded using the Harris hip score (HHS) and The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Pain and satisfaction were assessed using a visual analogue scale (VAS). Radiographic analysis was performed by evaluating osteolysis, stress shielding, alignment and signs of aseptic loosening. Complications were documented. RESULTS: At last follow-up the mean EQ-5D-5L index was 0.851 (SD 0.098). Clinical outcome was excellent (HHS ≥ 90) in 4 patients and moderate (HHS 71 and 79) in 2 patients. The mean WOMAC score was 9.20% (SD 12.61%). Pain and satisfaction on VAS were 1.00 (SD 1.15) and 9.17 (SD 0.37), respectively. No major complications occurred. To date, no further revision surgery was needed. Radiologically, no signs of subsidence, aseptic loosening, stress shielding and fractures were obvious. CONCLUSION: The present case series indicates that in failed conventional THA downsizing may be considered a treatment option, using short stem THA in selected cases.

The concept of a cementless isoelastic monoblock cup made of highly cross-linked polyethylene infused with vitamin E: radiological analyses of migration and wear using EBRA and clinical outcomes at mid-term follow-up.

BACKGROUND: The newest generation of cementless titanium-coated, isoelastic monoblock cup with vitamin E-blended highly cross-linked polyethylene (HXLPE) was introduced to the market in 2009. The aim of the present study was to obtain mid-term follow-up data including migration and wear analyses. METHODS: This prospective study investigated 101 primary total hip arthroplasty (THA) cases in 96 patients treated at a single institution. Patients were allowed full weight-bearing on the first day postoperatively. Harris hip score (HHS) and pain and satisfication on a visual analogue scale (VAS) were assessed at a mean follow-up of 79.0 months. Migration and wear were assessed using Einzel-Bild-Roentgen-Analyse (EBRA) software. Radiological acetabular bone alterations and complications were documented. RESULTS: At mid-term follow-up (mean 79.0 months, range: 51.8-101.7), 81 cases with complete clinical and radiological data were analyzed. Utilisable EBRA measurements were obtained for 42 hips. The mean HHS was 91.1 (range 38.0-100.0), VAS satisfaction was 9.6 (range 6.0-10.0), VAS rest pain was 0.2 (range 0.0-4.0), and VAS load pain was 0.6 (range 0.0-9.0). Mean migration was 0.86 mm (range: 0.0-2.56) at 24 months and 1.34 mm (range: 0.09-3.14) at 5 years, and the mean annual migration rate was 0.22 (range: - 0.24-1.34). The mean total wear was 0.4 mm (range: 0.03-1.0), corresponding to a mean annual wear rate of 0.06 mm per year (range: 0.0-0.17). Radiographic analysis did not reveal any cases of osteolysis, and no revision surgeries had to be performed. CONCLUSIONS: After using vitamin-E blended HXLPE in cementless isoelastic monoblock cups, there were no obvious signs of osteolysis or aseptic loosening occurred. No patients required revision surgery after mid-term follow-up. Cup migration and wear values were well below the benchmarks considered predictive for potential future failure. TRIAL REGISTRATION: The trial registration number on ClinicalTrials.gov : NCT04322916 (retrospectively registered at 26.03.2020).

Primary stability of calcar-guided short-stem total hip arthroplasty in the treatment of osteonecrosis of the femoral head: migration analysis using EBRA-FCA.

INTRODUCTION: Osteonecrosis of the femoral head (ONFH) is a disabling condition that often results in secondary arthritis necessitating total hip arthroplasty (THA). Short-stem THA has constantly gained popularity. It remains controversial, whether ONFH represents a risk factor for failure after the implantation of short stems with pronounced metaphyseal anchorage. The potential spread of the osteonecrotic area and bone marrow edema into the metaphyseal bone might result in compromised stability. Early implant migration is considered predictive of subsequent aseptic loosening. The purpose of this study was a migration analysis of a modern, calcar-guided short-stem implant in patients with ONFH in a mid-term follow-up. MATERIALS AND METHODS: This retrospective analysis investigated the migration pattern of 45 calcar-guided short stems in patients with ONFH, using Einzel-Bild-Roentgen-Analyse Femoral-Component-Analysis (EBRA-FCA). Influencing factors such as ARCO categories, age, gender, body weight and BMI were analyzed. Complications and adverse events were documented. RESULTS: At mid-term [48.1 months (SD 20.7 months)], mean axial migration was 1.56 mm (SD 1.77 mm). Mean migration rate stabilized after 2 years. No influence of ARCO categories, age and BMI was found. A tendency of increased axial migration was observed in male patients and in overweight patients. No revision surgeries had to be performed during follow-up. CONCLUSION: The results indicate a migration pattern comparable to that of primary osteoarthritis patients with slight initial migration under full load followed by subsequent stabilization in the metaphyseal femur. The 100% survival rate at mid-term supports the usage of this short-stem design in patients with ONFH.

Correction to: Does increased femoral antetorsion predispose to cartilage lesions of the patellofemoral joint?

Unfortunately, the following reference was not included in the original publication of the article.

Mid-term results of a new-generation calcar-guided short stem in THA: clinical and radiological 5-year follow-up of 216 cases.

BACKGROUND: In recent years, a variety of short stems have been introduced. To date, mid- and long-term results of calcar-guided short-stem designs have been rarely available. MATERIALS AND METHODS: Two hundred and sixteen calcar-guided short stems were included in combination with a cementless cup in a prospective study. Patients were allowed full weight-bearing on the first day postoperatively. Harris hip score (HHS) as well as pain and satisfaction on visual analogue scale (VAS) were assessed during a median follow-up of 61.7 months. Standardised radiographs were analysed at predefined time points regarding radiological alterations such as bone resorption and remodelling, radiolucency, osteolysis and cortical hypertrophy using modified Gruen zones. RESULTS: At mid-term follow-up, no revision surgery of the stem had to be performed in the whole collective. At 5 years, HHS was 97.8 (SD 4.7), satisfaction on VAS was 9.7 (SD 0.7), rest pain on VAS was 0.1 (SD 0.5), and load pain on VAS was 0.6 (SD 1.2). Compared to the 2-year results, femoral bone resorption increased significantly at the 5-year follow-up (3.9% versus 42.3%). Rate of femoral cortical hypertrophy remained stable, occurring in a total of 9 hips (4.5%). At the 5-year follow-up, 2 stems (1.0%) showed non-progressive radiolucent lines with a maximum width of 2 mm. Signs of osteolysis were not observed. Compared to the 2-year follow-up, no further subsidence was observed. CONCLUSIONS: The rate of stem revision (0%) at the mid-term follow-up was remarkable and indicates the principle of using a calcar-guided short stem as being a safe procedure. However, signs of bone-remodelling, indicating some amount of stress-shielding, must be acknowledged at 5 years depending on stem alignment and type of anchorage. LEVEL OF EVIDENCE: IV, Prospective observational study Trial registration German Clinical Trials Register, DRKS00012634, 07/07/2017 (retrospectively registered).

No benefit of autologous transfusion drains in total knee arthroplasty.

PURPOSE AND HYPOTHESIS: Autologous blood transfusion drains are commonly used to reduce allogeneic blood transfusion rate after total knee arthroplasty. There is conflicting evidence as to whether autologous transfusion drains (ABT drains) were effective when restrictive transfusion triggers were used. The aim of our study was to ascertain where, as a part of a blood management protocol, autologous blood transfusion drains reduce the allogeneic blood transfusion rate after total knee arthroplasty. METHODS: Two-hundred total knee arthroplasty patients were included in the prospective randomized controlled study. After implantation, a Redon drain without vacuum assistance (control, n = 100) or an autologous blood transfusion drain (ABT group, n = 100) was used. Demographic and operative data were collected. The blood loss, total blood loss, blood values and transfusion rate were documented. RESULTS: The blood loss in the drains was significantly increased for the ABT group (409 vs. 297 ml, p < 0.001). There was a non-significant trend towards a higher total blood loss for ABT patients (1844 vs. 1685 ml, n.s.). The allogeneic blood transfusion rate was similar for both groups (8 vs. 9%, n.s.). Similarly, the number of transfused blood units was comparable between both groups (0.2U/patient vs. 0.17U/patient n.s.). CONCLUSION: In combination with restrictive blood transfusion triggers, ABT drains had no positive effect on the allogeneic blood transfusion rate. The blood loss in ABT drains was higher. As a consequence, the use of ABT drains was discontinued. LEVEL OF EVIDENCE: I.

Reconstruction of the lateral ulnar collateral ligament of the elbow: a comparative biomechanical study.

PURPOSE: Posterolateral rotatory instability (PLRI) of the elbow is the result of an insufficient lateral collateral ligament complex (LCLC). Single-bundle reconstruction of the lateral ulnar collateral ligament (LUCL) represents the standard treatment method for chronic PLRI. However, cases of recurrent instability after LUCL reconstruction have been reported. The dual-reconstruction procedure has been described to anatomically restore the LUCL as well as the radial collateral ligament (RCL). It was hypothesized that anatomic reconstruction of the LCLC provides increased stability compared with the conventional technique. METHODS: Posterolateral rotatory displacement was assessed in eight fresh-frozen human elbows with a maximum load of 20 N. Data were obtained in 0°, 30°, 60°, 90° and 120° of elbow flexion for native specimens, dissected LCLC and three reconstruction methods: (1) single-bundle LUCL reconstruction, (2) single-bundle LUCL reconstruction with RCL augmentation, (3) dual-reconstruction technique (LUCL + RCL). RESULTS: All reconstruction methods were able to sufficiently restore posterolateral rotatory stability of the elbow over the full range of motion. There were no significant differences between the intact specimens and either reconstruction method. Dissection of the LCLC significantly increased PLRI compared with the other groups (p < 0.001). CONCLUSION: The less invasive dual-reconstruction technique is confirmed as a safe procedure for anatomic LCLC reconstruction. Primary stability is equal, yet not superior to conventional LUCL reconstruction. Hence, this biomechanical study does not confirm the hypothesis that more anatomic reconstruction techniques could reduce the risk of recurrent instability when compared to conventional LUCL reconstruction.

Does increased femoral antetorsion predispose to cartilage lesions of the patellofemoral joint?

PURPOSE: The purpose of this study was to investigate whether there was a relationship between femoral neck antetorsion and the presence and pattern of osteoarthritis of the patellofemoral joint. It was hypothesized that an increased femoral neck antetorsion (1) correlates with osteoarthritic changes of the lateral facet of the patellofemoral joint and (2) correlates with an increased lateral trochlear height and a decreased sulcus angle. METHODS: Seventy-eight formalin-embedded cadaveric lower extremities from thirty-nine subjects with a median age of 74 years (range 60-88) were used. Surrounding soft tissues of the lower limb were removed. The femoral neck antetorsion was measured and referenced to the transepicondylar axis and the posterior condylar line. The height of the medial and lateral facet of the trochlea and the sulcus angle was measured. The location and the degree of patellofemoral cartilage degeneration were recorded. A Pearson's correlation analysis was performed to correlate the femoral neck antetorsion with the measured knee parameters. RESULTS: No significant correlation could be found between the femoral antetorsion and cartilage degeneration of the lateral patellofemoral joint (n.s.), the height of the lateral trochlea (n.s.) and the sulcus angle (n.s.). CONCLUSION: This study could not document that the femoral neck antetorsion and subsequent internal rotation of the distal femur correlated with the degree of degeneration of the lateral facet of the patellofemoral joint. Clinically, femoral internal rotation may play a minor role in the development of lateral patellofemoral joint degeneration.

Low Short-Stem Revision Rates: 1-11 Year Results From 1888 Total Hip Arthroplasties.

BACKGROUND: In total hip arthroplasty, short stems were developed as a bone-conserving alternative to traditional cementless stems. So far, there have been very few recorded medium to long-term results of these comparatively new implants. The aim of our retrospective study was to report on the survival of calcar-loading short stems. METHODS: All Metha stem implantations from 2004 to 2014 were recorded from the operation protocols (n = 1888). Due to the chronological development of the stem, 3 different versions were implanted: modular titanium stems with neck adapters from titanium or cobalt-chrome and monoblock stems. Patients were questioned by post about revision, dislocation, and satisfaction. RESULTS: Data were complete for 93% of the procedures (1090 monoblock stems, 314 modular stems with titanium neck, and 230 modular stems with cobalt chrome neck). Mean follow-up was 6 years (1-11 years). Fifteen modular titanium implants were affected by cone fractures (4%). Therefore, monoblock, modular cobalt chrome, and modular titanium implants were analyzed separately. The 7-year revision rate for monoblock stems was 1.5%; for modular cobalt-chrome stems it was 1.8%, and for modular titanium stems it was 5.3%. CONCLUSION: Our data show the midterm survival of the monoblock and modular cobalt-chrome implants equivalent to the traditional cementless stems. These might, therefore, be considered as a bone-conserving alternative for young and active patients.

The femoral neck-shaft angle on plain radiographs: a systematic review.

OBJECTIVE: The femoral neck-shaft angle (NSA) is an important measure for the assessment of the anatomy of the hip and planning of operations. Despite its common use, there remains disagreement concerning the method of measurement and the correction of hip rotation and femoral version of the projected NSA on conventional radiographs. We addressed the following questions: (1) What are the reported values for NSA in normal adult subjects and in osteoarthritis? (2) Is there a difference between non-corrected and rotation-corrected measurements? (3) Which methods are used for measuring the NSA on plain radiographs? (4) What could be learned from an analysis of the intra- and interobserver reliability? MATERIAL AND METHODS: A systematic literature search was performed including 26 publications reporting the measurement of the NSA on conventional radiographs. RESULTS: The mean NSA of healthy adults (5,089 hips) was 128.8° (98-180°) and 131.5° (115-155°) in patients with osteoarthritis (1230 hips). The mean NSA was 128.5° (127-130.5°) for the rotation-corrected and 129.5° (119.6-151°) for the non-corrected measurements. CONCLUSION: Our data showed a high variance of the reported neck-shaft angles. Notably, we identified the inconsistency of the published methods of measurement as a central issue. The reported effect of rotation-correction cannot be reliably verified.

The neck shaft angle: CT reference values of 800 adult hips.

OBJECTIVE: A precise understanding of the radiological anatomy and biomechanics as well as reliable reference values of the hip are essential. The primary goal of this study was to provide reference values of the neck-shaft angle (NSA) for adult patients based on the analysis of rotation corrected computed tomography (CT) scans of 800 hips. The secondary aim was to compare these measurements with simulated anteroposterior roentgenograms of the pelvis. MATERIALS AND METHODS: Pelvic CT scans of 400 patients (54.3 years, range 18-100 years; 200 female) were reconstructed in the derotated coronal plane of the proximal femur and as CT-based simulated anteroposterior roentgenograms of the pelvis in the anterior pelvic plane. Femora were categorized as coxa vara (<120°), physiologic (≥120° to <135°), and coxa valga (≥135°). Intra- and inter-rater reliability were analyzed. RESULTS: Primary research question: Mean NSA for male adults was 129.6° (range 113.2°-148.2°; SD 5.9°) and 131.9° (range 107.1°-151.9°; SD 6.8°) for females in derotated coronal reconstructions. Age (p < 0.001 in both views) and sex influenced the NSA significantly (p = 0.002 and p < 0.001); no significant differences were found between sides (p = 0.722 and p = 0.955). Overall, an excellent reliability of repeated measurements of one or two observers was found (ICC 0.891-0.995). Secondary research question: NSA values measured in the simulated anteroposterior roentgenogram and the rotation corrected coronal reconstruction differed significantly (p < 0.001). CONCLUSIONS: While anteroposterior pelvis radiographs are susceptible to rotational errors, the coronal reconstruction of the proximal femur in the femoral neck plane allows the correct measurement of the NSA.

Agreement Between Proximal Femoral Geometry and Component Design in Total Hip Arthroplasty: Implications for Implant Choice.

BACKGROUND: The present study aimed to analyze the agreement between proximal femoral geometry of adult hips and femoral component design in total hip arthroplasty. METHODS: Anatomical femoral offset (FOAnat) and the anatomical neck-shaft angle (NSAAnat) of 800 adult hips were measured by computed tomography scans, and anatomical femoral neck height (FHAnat) was calculated. Corresponding best-fit implants of the most common hip system (standard, high offset and varus variant) were identified for each hip. Finally, the precision of the best possible anatomic reconstruction was assessed. RESULTS: The mean FOAnat was 38.0 mm (range: 19.8-57.9 mm, standard deviation [SD]: 6.4 mm), the mean NSAAnat was 130.8° (range: 107.1°-151.9°; SD: 6.5°), and the mean FHAnat was 32.6 mm (range: 14.4-52.0 mm; SD: 5.5 mm). In 450 (56.3%) hips, the standard variant was identified to be the best-fit implant, followed by the varus (n = 282, 35.3%) and the high offset (n = 68, 8.5%) variants. The mean minimal distance from the best-fit implant was 4.5 mm (range: 0.1-20.2 mm, SD: 3.4 mm). Excellent agreement (distance: <2 mm) between hip anatomy and best-fit implant was found in 203 (25.4%) hips, combined excellent and acceptable agreement (distance: <6 mm) in 569 (71.1%) hips, whereas 213 (28.9%) hips were graded as poor (distance: ≥6 mm). CONCLUSION: The present study revealed a mismatch between proximal femoral anatomy of a relevant proportion of adult hips and implant geometry of the most common femoral component in total hip arthroplasty.

Calibration Marker Position in Digital Templating of Total Hip Arthroplasty.

BACKGROUND: We report a mathematical method to assess the vertical and horizontal positions of spherical radiopaque objects of known size in conventional radiographs. METHODS: The reliability and validity of the method were tested in an experimental setting and applied to 100 anteroposterior pelvic radiographs with external calibration markers and unilateral total hip arthroplasty (THA). RESULTS: We found excellent reliabilities; intraclass correlation coefficients for interobserver and intraobserver reliabilities were 0.999-1.000 (P = .000). The mean normal height of THA was 198 mm (range: 142-243 mm, standard deviation: 18 mm) above the detector. Vertical and horizontal external marker positions differed significantly from the true hip center (THA; P < .001 and P = .017). CONCLUSION: This method could enhance patient safety by enabling automated detection of malpositioned calibration markers by templating software.

Mallet finger: a simulation and analysis of hyperflexion versus hyperextension injuries.

The goal of this study was to simulate the mechanisms of hyperflexion and hyperextension injuries of the distal interphalangeal (DIP) joint of the hand and to analyze the resulting extensor tendon injury patterns. The hypotheses were raised that hyperflexion trauma leads to a plastic deformation of the extensor tendon aponeurosis, with or without a small bony avulsion fragment but without joint surface involvement, and that hyperextension injuries can create a shear fracture of the dorsal lip of the distal phalanx, without injury to the extensor tendon aponeurosis. Loading was applied with a swinging pendulum impacting the distal phalanx in 103 human specimens in either an extended or flexion position. After loading, injury patterns were analyzed radiologically and histologically. There was evidence that hyperflexion trauma leads to a plastic deformation or rupture of the extensor tendon. Bony tendon avulsion was evident in 12.2 % of cases. With hyperextension, the extensor tendon remained intact in all cases, but there were large fracture fragments involving the articular surface in 4.1 % of cases. The results of the study show that force on the flexed joint leads to overstretching of the extensor tendon, and to an associated dorsal bony avulsion with intact joint line. Force applied to the joint in extension can lead to a bony dorsal edge fracture with articular involvement and with it, a palmar DIP joint capsule rupture. The results illuminate a direct correlation between the mechanism of injury and the pattern of injury in the clinical picture of mallet finger.

Graft diameter does not influence primary stability of ulnar collateral ligament reconstruction of the elbow.

BACKGROUND: Ulnar collateral ligament insufficiency may result in medial elbow pain, instability, and reduced athletic performance in throwing athletes. Several reconstruction methods have been described, but biomechanical studies suggest that in general, stability of the graft construct is inferior to the native ulnar collateral ligament. This study investigates whether a stronger graft would yield greater resistance to valgus load over the range of motion. METHODS: Ten cadaveric elbows were mounted to a testing fixture and incremental valgus moments of 2.5, 5, and 7.5 Nm were applied with the elbow in 120°, 90°, 60°, 30° and 0° of flexion and in varying rotational forearm positions. The intact and the ulnar collateral ligament released elbow joint were compared with the docking ulnar collateral ligament reconstruction technique, using different graft sources with increasing cross-sectional areas: palmaris longus, tricpes brachii, extensor carpi radialis longus, and semitendinosus. The resulting angular displacement was evaluated and compared between graft sources and different elbow positions. RESULTS: Compared with the intact situation, ulnar collateral ligament release resulted in a significant increase in valgus deformation over the entire range of flexion-extension motion. Ligament reconstruction using any graft source significantly restored valgus stability at 60°, 90°, and 120°, while at 0° and 30°, angular valgus deformation did not significantly differ from the ulnar collateral ligament deficient situation. There were no significant differences in angular valgus deformation between the graft sources over the range of flexion motion or forearm rotation. CONCLUSIONS: This study did not prove that a thicker graft yielded more resistance to valgus moments when using the docking technique. Thicker grafts require larger bone tunnels, cannot be adequately tensioned, and are non-anatomic. Therefore, the palmaris longus or a triceps tendon strip are considered more appropriate for ulnar collateral ligament reconstruction.

Distal radius: anatomical morphometric gender characteristics. Do anatomical pre-shaped plates pay attention on it?

INTRODUCTION: The purpose of the study was to investigate differences in the osseous structure anatomy of male and female distal radii. METHODS: Morphometric data were obtained of 49 distal human cadaveric radii. An imprint of the distal edge was attained using silicone mass and the palmar cortical angle (PCA) of the lateral and intermediate column, here declared as medial, according to the concept of Rikli and Rigazzoni. The lateral and medial length and five widths were digitally measured by three observers. In order to compare the measurements an unpaired t test was used. To prove the reliability of the measurements an intraclass correlation analyses was done. RESULTS: Overall mean medial PCA was 148.25° (SD ± 6.83) and mean lateral PCA 156.07° (SD ± 7.00). In male specimens, the mean medial PCA was 147.38° (SD ± 6.01) and mean lateral PCA was 153.6° (SD ± 6.20) whereas in female specimens, the mean medial PCA was 149.41° (SD ± 7.79) and the mean lateral PCA 159.37° (SD ± 6.78), with statistical significance for the female lateral PCA. No gender significant difference for the medial PCA and no significant side difference for the PCA's could be found. The ICC of the observers was r = 0.936 and 0.976 for the medial and for lateral PCA 0.957-0.984. The palmar cortical length of the distal radius was significantly longer in male specimens. For all widths, larger values for male radii were measured, being statistically significant in all cases. CONCLUSION: Male dimensions concerning the wide were significantly larger when compared with females. Regarding the PCA at the medial and lateral column, we found significant difference for lateral PCA concerning the gender. Overall, study results demonstrated an angle of 148.25° ± 6.83 for the medial PCA and 156.07° ± 7.00 for the lateral PCA.

Fracture reduction with positive medial cortical support: a key element in stability reconstruction for the unstable pertrochanteric hip fractures.

PURPOSE: To introduce the concept of fracture reduction with positive medial cortical support and its clinical and radiological correlation in geriatric unstable pertrochanteric fractures. METHODS: A retrospective analysis of 127 patients (32 men and 95 women, with mean age 78.7 years) with AO/OTA 31A2.2 and 2.3 hip fractures treated with cephalomedullary nail (PFNA-II or Gamma-3) between July 2010 and June 2013 was performed. They were classified into three groups according the grade of medial cortical support in postoperative fracture reduction (positive, neutral, and negative). The positive cortex support was defined that the medial cortex of the head-neck fragment displaced and located a little bit superomedially to the medial cortex of the shaft. If the neck cortex is located laterally to the shaft, it is negative with no cortical buttress, and if the two cortices contact smoothly, it is in neutral position. The demographic baseline, postoperative radiographic femoral neck-shaft angle and neck length, rehabilitation progress and functional recovery scores of each group were recorded and compared. RESULTS: There were 89 cases (70 %) in positive, 26 in neutral, and 12 in negative support. No statistical differences were found between the three groups among patient age, sex ratio, prefracture score of activity of daily living, walking ability score, ASA physical risk score, number of medical comorbidities, osteoporosis Singh index, fracture reduction quality (Garden alignments), and the position of lag screw or helical blade in femoral head (TAD). In follow-up, patients in positive medial cortical support reduction group had the least loss in neck-shaft angle and neck length, and got ground-walking much earlier than negative reduction group, with good functional outcomes and less hip-thigh pain presence. CONCLUSION: Fracture reduction with nonanatomic positive medial cortical support allows limited sliding of the head-neck fragment to contact with the femur shaft and achieve secondary stability, providing a good mechanical environment for fracture healing.

A surgical protocol for bicondylar four-quadrant tibial plateau fractures.

PURPOSE: Bicondylar tibial plateau fractures involving four articular quadrants are severe and complex injuries, and they remain a challenging problem in orthopaedic trauma. The aim of this study was to introduce a new treatment protocol with dual-incision and multi-plate fixation in the floating supine patient position as well as to report the preliminary clinical results. METHODS: From January 2006 to December 2011, 16 consecutive patients with closed bicondylar four-quadrant tibial plateau fractures (Schatzker type VI, OTA/AO 41C2/3) were treated with posteromedial inverted L-shaped and anterolateral incisions. With the posteromedial approach, three quadrants (posteromedial, anteromedial and posterolateral) can be exposed, reduced and fixed with multiple small antiglide plates and short screws in an enclosure pattern. With the anterolateral approach, after articular elevation and bone substitute grafting, a strong locking plate with long screws to the medial cortex is used to raft-buttress the reduced lateral plateau fracture, hold the entire reconstructed tibial condyles together, and contact the condyles with the tibial shaft. All patients were encouraged to exercise knee motion at an early stage. The outcome was evaluated clinically and radiologically after a minimum two-year follow-up. RESULTS: The average operation time was 98 ± 26 minutes (range 70-128) and the average duration of hospitalization was 29 ± 8.6 days (range 20-41). Three cases used five plates, nine cases used four plates, and four cases used three plates. All patients were followed for a mean of 28.7 ± 6.1 months (range 26-38). Fifteen incisions healed initially, while one patient developed a medial wound dehiscence and was successfully managed by debridement. All patients achieved radiological fracture union after an average of 20.2 weeks. At the two-year follow up, the average knee range of motion (ROM) was 98° ± 13.7 (range 88-125°), with a Hospital for Special Surgery (HSS) knee score of 87.7 ± 10.3 (range 75-95), and SMFA score of 21.3 ± 8.6 (range 12-33). CONCLUSION: For bicondylar four-quadrant tibial plateau fractures, the treatment protocol of multiple medial-posterior small plates combined with a lateral strong locking plate through dual incisions can provide stable fracture fixation to allow for early stage rehabilitation. Good clinical outcomes can be anticipated.