Biomechanical Research of Three Parallel Cannulated Compression Screws in Oblique Triangle Configuration for Fixation of Femoral Neck Unstable Fractures.

OBJECTIVE: Surgical treatment with internal fixation, specifically percutaneous fixation with three cannulated compression screws (CCSs), is the preferred choice for young and middle-aged patients. The mechanical advantage of the optimal spatial configuration with three screws provides maximum dispersion and cortical support. We suspect that the spatial proportion of the oblique triangle configuration (OTC) in the cross-section of the femoral neck isthmus (FNI) may significantly improve shear and fatigue resistance of the fixed structure, thereby stabilizing the internal fixation system in femoral neck fracture (FNF). This study aims to explore the mechanical features of OTC and provide a mechanical basis for its clinical application. METHODS: Twenty Sawbone femurs were prepared as Pauwels type III FNF models and divided equally into two fixation groups: OTC and inverted equilateral triangle configuration (IETC). Three 7.3 mm diameter cannulated compression screws (CCSs) were used for fixation. The specimens of FNF after screw internal fixation were subjected to static loading and cyclic loading tests, respectively, with five specimens for each test. Axial stiffness, 5 mm failure load, ultimate load, shear displacement, and frontal rotational angle of two fragments were evaluated. In the cyclic loading test, the load sizes were 700 N, 1400 N, and 2100 N, respectively, and the fracture end displacement was recorded. Results were presented as means ± SD. Data with normal distributions were compared by the Student's t test. RESULTS: In the static loading test, the axial stiffness, ultimate load, shear displacement, and frontal rotational angle of two fragments were (738.64 vs. 620.74) N/mm, (2957.61 vs. 2643.06) N, (4.67 vs. 5.39) mm, and (4.01 vs. 5.52)° (p < 0.05), respectively. Comparison between the femoral head displacement after 10,000 cycles of 700N cyclic loading and total displacement after 20,000 cycles of 700-1400N cyclic loading showed the OTC group was less than the IETC group (p < 0.05). A comparison of femoral head displacement after 10,000 cycles of 1400N and 2100N cycles and total displacement after 30,000 cycles of 700-2100N cycles showed the OTC group was less than another group, but the difference was not significant (p > 0.05). CONCLUSION: When three CCSs are inserted in parallel to fix FNF, the OTC of three screws has obvious biomechanical advantages, especially in shear resistance and early postoperative weight-bearing, which provides a mechanical basis for clinical selection of ideal spatial configuration for unstable FNF.

Biomechanical Analysis of Headless Compression Screw Versus Tension Band Wiring for Proximal Interphalangeal Joint Arthrodesis.

PURPOSE: Proximal interphalangeal (PIP) joint arthrodesis is a procedure employed to address arthritis, instability, and deformity. Multiple fixation methods are available to maintain stability across the arthrodesis interval, including headless compression screws (HCSs), tension band wiring (TBW), plating, and Kirschner wire constructs. The purpose of this study was to compare the biomechanical properties of the HCS and TBW techniques. METHODS: Thirty-two nonthumb digits from the paired upper limbs of four fresh frozen cadavers were divided into pairs, matching contralateral digits from the same specimen. One PIP joint of each pair was fused with an antegrade 3.5 mm HCS, and the second was fused with TBW using 0.035 in. Kirschner wires with 24-gauge dental wire. Each construct was then stressed to 10 N in the radial deviation, ulnar deviation, flexion, and extension planes, and stiffness (N/mm) was calculated. The fingers were stressed to failure in extension with the ultimate load and mode of failure recorded. RESULTS: When stressed in extension, the HCS construct had a significantly greater mean stiffness than the TBW construct (16.4 N/mm vs 10.8 N/mm). The stiffness in all other planes of motion were similar between the two constructs. The mean ultimate load to failure in extension was 91.4 N for the HCS and 41.9 N for the TBW. The most common mode of failure was fracture of the dorsal lip of the proximal phalanx (13/16) for the HCS and bending of the K-wires (15/16) for TBW. CONCLUSIONS: Arthrodesis of the PIP joint using a HCS resulted in a construct that was significantly stiffer in extension with greater than double the load to failure compared to TBW. CLINICAL RELEVANCE: Although the stiffness required to achieve successful PIP joint arthrodesis has not been well quantified, the HCS proved to be the most favorable construct with respect to initial strength and stability.

[Finite element analysis of the stability of Mason type â ¢ radial head fracture fixed with three cross-bridge headless compression screw and locking plate].

OBJECTIVE: To compare the biomechanical stability of three cross-bridge headless compression screws and locking plates in the fixation of Mason type Ⅲ radial head fractures by finite element method. METHODS: Using reverse modeling technology, the radial CT data and internal fixation data of a healthy 25-year-old male were imported into the relevant software. Three-dimensional finite element model of 3 cross-bridge headless compression screws and locking plates for MasonⅢ radial head fractures were established, and the radial head was loaded with 100 N axial loading. The maximum displacement, maximum Von Mises stress and stress distribution of the two groups were compared. RESULTS: The maximum displacements of the three cross-bridge screws group and locking plate group were 0.069 mm and 0.087 mm respectively, and the Von Mises stress peaks were 18.59 MPa and 31.85 MPa respectively. The stress distribution of the three screws group was more uniform. CONCLUSION: Both internal fixation methods can provide good fixation effect. CoMPared with the locking plate fixation method, the 3 cross-bridge headless compression screws fixation is more stable and the stress distribution is more uniform.

Compression screw internal fixation versus non-weight-bearing cast immobilization for Jones fractures in children.

BACKGROUND: Several methods have been used to treat pediatric Jones fractures, but there has been no consensus about the optimum method. The purposes of this study were to compare the clinical outcomes between compression screw and non-weight-bearing techniques used in pediatric Jones fractures and clarify the most suitable treatment option for this population. METHODS: Twenty-one patients who presented with Jones fractures between January 2015 and June 2021 were analyzed retrospectively. They were divided into the compression screw group (n=10) and cast immobilization (n=11) group. The following parameters were compared between them: demographic data; times to radiographic union, full weight bearing, and return to daily life; and the American Orthopaedic Foot and Ankle Society (AOFAS) foot scores at 3 months postoperatively and the final follow-up. RESULTS: The two groups did not differ significantly with respect to age, sex, laterality, and preoperative displacement. The mean immobilization time and times to radiographic union, full weight bearing, and return to daily life were significantly shorter in the compression screw group than in the cast immobilization group. The AOFAS scores at the final follow-up did not differ significantly between the two groups. One case of refracture and delayed union each were observed in the non-weight-bearing cast group. However, no patients experienced nonunion. CONCLUSIONS: Compression screw and non-weight-bearing cast techniques are effective methods for treating pediatric Jones fractures. The complication rate was lower in pediatrics than in adults. However, compared with the non-weight-bearing cast technique, the compression screw technique has the advantages of a shorter radiographic union time, shorter immobilization times, and earlier return to full weight bearing and daily life. We recommend compression screw fixation for widely displaced fractures and school-age and active adolescents to avoid delays in healing, nonunion, disruption to daily living, and time off school. LEVEL OF EVIDENCE: Level III.

A biomechanical comparison of the double-row suture fixation and compression screw techniques in the treatment of lateral malleolar avulsion fracture.

Background: Avulsion fractures of fibula occur with ankle sprains. The purpose of this study was to compare the biomechanical characteristics of double-row suture versus compression screw techniques in treatment of lateral malleolar avulsion fracturelarger than 10 mm in size, which is typically not associated with an anterior talofibular ligament injury. Methods: We simulated lateral malleolus avulsion fractures in six matched pairs of 12 human cadaveric ankles. These were then randomly divided into two groups: a double-row fixation group and a compression screw group. Biomechanical testing was performed after surgical fixation. The foot was rotated from the neutral position toward inversion at a rate of 1°/s until 12.5 N-m or structural failure was reached. The final rotation torque, rotation angle, stiffness, and displacement of the ossicles were recorded. Results: No significant difference was found in the final rotation torque (7.60 ± 3.70 vs 7.23 ± 2.06 N-m, p = 0.87), rotation angle (43.61 ± 14.77° vs 40.93 ± 10.94°, p = 0.56), stiffness (0.19 ± 0.08 vs 0.13 ± 0.07, p = 0.33), or displacement (6.11 ± 5.23 vs 7.09 ± 5.93 mm, p = 0.77) between the two groups. Conclusions: The stability of the double-row suture fixation was equivalent to compression screw fixation in treating a lateral malleolar avulsion fracture larger than 10 mm in size with ligament injury, as determined by our biomechanical testing.

Unusual case report of concomitant lunate and scaphoid fractures without associated dislocation in a 16-year-old male.

INTRODUCTION AND IMPORTANCE: Lunate fractures without associated dislocations are rare injuries, combination scaphoid-lunate fractures without an associated dislocation are even more rare of which few are reported in the literature. CASE PRESENTATION: This case report describes a 16-year-old otherwise healthy male with ipsilateral scaphoid and lunate fractures after punching a goalpost with his left hand, for which he had surgical management. This patient had a successful treatment with two headless compression screws through a single extended carpal tunnel approach. Surgery was performed within two weeks of injury after initially immobilized with a thumb spica splint. The postoperative period was complicated by noncompliance with weight-bearing status and missed three-month followup. However, by six months, subsequent visits demonstrated radiographic and clinical healing as well as full wrist range of motion without any other sequelae. CLINICAL DISCUSSION: This case offers more evidence regarding this rare injury. Lunate fractures and scaphoid fractures can both be treated with open reduction and internal fixation using headless compression screws, however little evidence exists when it comes to treating them in combination. CONCLUSION: The use of headless compression screws through a single extended carpal tunnel approach led to clinical and radiographic healing in a 16 year-old-male with combined scaphoid and lunate fractures at 6 month follow up.

[Treatment of Ideberg type â ¡ scapular glenoid fracture with compression screw combined with Buttress plate through direct axillary approach].

Objective: To investigate the effectiveness of compression screw combined with Buttress plate through direct axillary approach for Ideberg typeⅡ scapular glenoid fractures. Methods: A retrospective analysis was conducted on 11 patients with Ideberg type Ⅱ scapular glenoid fractures treated with compression screws combined with Buttress plate fixation through the direct axillary approach between January 2014 and June 2022. There were 7 males and 4 females, aged from 34 to 75 years, with an average of 56.0 years. The causes of injury included 4 cases of falling from height injury, 4 cases of heavy object injury, and 3 cases of traffic accident injury. The time from injury to operation was 2-5 days, with an average of 3.8 days. The operation time, intraoperative blood loss, hospital stay, complications, and fracture healing time were recorded. The Constant-Murley score, American Society of Shoulder and Elbow Surgeons (ASES) score, and shoulder joint flexion, abduction, external rotation (neutral position), and internal rotation (neutral position) range of motion were used to evaluate shoulder joint pain and function. Results: The operation time was 45-105 minutes, with an average of 79.0 minutes; the intraoperative blood loss was 80-200 mL, with an average of 99.2 mL; the hospital stay was 3-8 days, with an average of 5.8 days. One patient had poor wound healing after operation, and the wound healed after strengthening dressing change; the rest wounds had primary healing, and no axillary nerve paralysis occurred. Except for 1 patient lost follow-up, the remaining 10 patients were followed up 10-54 months, with an average of 26.4 months. The postoperative X-ray film examination showed that the fractures healed well within 8-15 weeks, with an average of 11.0 weeks. There was no complication such as fracture displacement, internal fixator failure or fracture during follow-up. At last follow-up, the patient's shoulder joint flexion, abduction, external rotation (neutral position), and internal rotation (neutral position) range of motion, Constant-Murley score, and ASES score significantly improved when compared with those before operation ( P<0.05). Conclusion: Compression screw combined with Buttress plate through direct axillary approach is an effective way to treat Ideberg typeⅡ scapular glenoid fracture, with advantages of small trauma, concealed incision, and good effectiveness.

Surgical management of neck of femur fractures in patients younger than sixty-five years: a comparative study of three fixation methods.

PURPOSE: Several surgical implants have been used for the treatment of neck of femur fracture (NOF) in younger patients such as dynamic hip screw (DHS) and cannulated compression screw. However, the superiority of one or another osteosynthesis device remains a matter of debate. The aim of this work is to evaluate and compare three fixation modalities: Cannulated Hip Screws (CHS), DHS and DHS associated to anti-rotating screw for surgical treatment of femoral neck fracture in young adults. METHODS: It is a retrospective comparative study of three series of NOF fractures treated surgically over a period of ten years; including young adult patients (age > 18 years and < 65 years) treated conservatively using closed or open reduction and internal fixation. All types of NOF fractures according to Garden classification were included. Pathological, basi-cervical fractures and fractures on previously operated hips were excluded. The minimum follow-up recommended was two years. Clinical evaluation was based on the Postel Merle d'Aubigné score (PMA), the visual analogue scale (VAS), the Parker score, and the Hip Disability and Osteoarthritis Outcome Score (HOOS score). Reduction quality was assessed on X-rays. RESULTS: Our series included 72 patients that were divided in three groups: Group A: Fixation using cannulated hip screws (33 patients). Group B: Fixation using DHS only (21 patients). Group C: Fixation using DHS associated to anti-rotation screw (18 patients). The patients of group A had better PMA and VAS scores, but there was no statistically significant difference. However, a significant difference (p=0.001) was found for the HOOS score. The fractures treated with DHS associated with anti-rotating screws, had the highest loss of reduction in the vertical axis (Yp) with the highest femoral head collapse (Zp) values. Group A had the lowest loss of reduction in the horizontal axis (Xp). There was no significant difference between the three methods of osteosynthesis in terms of loss of correction though. CONCLUSION: We found comparable results in terms of healing and complication rates and loss of reduction for the three groups with no significant difference. However, the HOOS score was significantly better in the cannulated hip screw group.

[Short term follow-up of unstable femoral neck fractures in young adults treated with femoral neck system and cannulated compression screws].

OBJECTIVE: To investigate the clinical efficacy of femoral neck system(FNS) and three cannulated compression screws(CCS) in the treatment of unstable femoral neck fractures in young adults. METHODS: The clinical data of 52 young and middle-aged patients with unstable femoral neck fractures admitted from August 2018 to August 2021 were reviewed and analyzed. All patients were divided into two groups according to the internal fixation method, 25 cases were treated with FNS fixation, 27 cases were treated with closed reduction and 3 CCS inverted triangular distribution. The operation time, incision length, intraoperative bleeding, hospitalization expenses and fracture reduction quality of two groups were recorded and compared;The patients were followed up regularly after operation. The fracture healing time, complete weight-bearing time and postoperative complications(nonunion, femoral neck shortening, femoral head necrosis) of two groups were compared. The Harris score was used to evaluate hip function 6 months after surgery. RESULTS: The operation was successfully completed in both groups. The patients in FNS group had more bleeding, longer incision length and higher hospitalization cost than CCS group(P<0.01). There ware no significant difference in operation time and Garden index between two groups(P>0.05). Patients in both groups were followed up for 6 to 32 months.The fracture healing time in FNS group was less than that in CCS group, the time of complete weight bearing after surgery was earlier than that in CCS group, and the hip Harris score was higher than that in CCS group (P<0.01). There were no internal fixation fracture complications in two groups during follow-up. In the FNS group, there were 4 cases of avascular necrosis of the femoral head and 2 cases of femoral neck shortening, of which 3 cases underwent total hip replacement due to avascular necrosis of the femoral head. In the CCS group, there were 2 cases of nonunion, 9 cases of avascular necrosis of the femoral head, and 11 cases of femoral neck shortening, among which 5 cases underwent total hip replacement due to nonunion and avascular necrosis of the femoral head. CONCLUSION: With simple operation, rotational stability and angular stability, FNS enables patients to start functional exercise as early as possible and reduces the incidence of postoperative complications of unstable femoral neck fracture. It is a new choice for the treatment of unstable femoral neck fracture in young adults.

A comparison of treatment between mini T-plate and headless cannulated compression screw in calcaneal osteotomy.

PURPOSE: In clinical studies, we discovered that when using headless cannulated compression screw fixation, many patients complain of heel pain and frequently need to have the screws removed, whereas this occurrence is uncommon with plate fixation. This study aims to compare the clinical outcome of a mini T-plate and headless cannulated compression screws in calcaneal osteotomy. METHODS: We reviewed the medical records of patients who had calcaneal osteotomy performed by one senior chief surgeon in our hospital between January 2014 and May 2021. Thirty-nine patients met the selection criteria: 22 were fixed using a mini T-plate through a modified small "L" incision on the lateral aspect of the calcaneus and 17 were fixed using double screws through an oblique incision on the lateral aspect of the calcaneus. Then, we compared the patient demographics, surgical statistics, and postoperative complications in calcaneal osteotomy between a mini T-plate and double 6.5-mm headless cannulated compressed screws. RESULTS: Each patient attained radiographic union. The average age was 49.23±13.80 (range: 24-76) years and the average follow-up duration was 47.07±8.64 (range: 36-66) weeks. The average operation duration and times of intraoperative fluoroscopy were significantly lower in the mini T-plate group (P<0.05). There was a savings of $838.88 per patient when using double screws for fixation. The incidence of hardware-related pain and implant removal was lower in the mini T-plate group (P<0.05). There is no significant difference between the two groups in terms of delayed incision healing and clinical neurological complications (P>0.05). CONCLUSIONS: In calcaneal osteotomy, the operation duration, times of intraoperative fluoroscopy, hardware-related pain, and implant removal rate were lower with mini T-plate fixation than with double screws fixation. Therefore, we consider that the mini T-plate would be a good alternative to double screws in calcaneal osteotomy.

Refixation of a Large Osteochondral Fragment with Magnesium Compression Screws-A Case Report.

INTRODUCTION: Osteochondrosis dissecans (OCD) is a disease affecting the subchondral bone and the overlying articular cartilage. The etiology is most likely a combination of biological and mechanical factors. The incidence is highest in children >12 years old and it predominantly affects the knee. In high-grade OCD lesions, free osteochondral fragments usually are refixed via titanium screws or biodegradable screws or pins. In this case, headless compression screws made from magnesium were used for refixation. CASE REPORT: A thirteen-year-old female patient with a two-year history of knee pain was diagnosed with an OCD lesion of the medial femoral condyle. After initial conservative treatment, displacement of the osteochondral fragment occurred. Refixation was performed using two headless magnesium compression screws. At the 6 months follow up, the patient was pain free, and the fragment showed progressive healing while the implants were biodegrading. DISCUSSION: Existing implants for refixation of OCD lesions either require subsequent removal or show less stability and possible inflammatory reactions. The new generation of magnesium screws used in this case did not lead to a gas release, as described for previous magnesium implants, while maintaining stability during continuous biodegradation. CONCLUSIONS: The data available to date on magnesium implants for the treatment of OCD are promising. However, the evidence on the magnesium implants in refixation surgery of OCD lesions is still limited. Further research needs to be conducted to provide data on outcomes and possible complications.

Tibiotalocalcaneal Arthrodesis: A Retrospective Comparison Between Nails and Lateral Locking Plate Complications.

Background: Tibiotalocalcaneal arthrodesis is a well-established procedure to treat some hindfoot diseases. Currently, the most used implants are retrograde intramedullary nails and locking plates combined with lag screws, but there are few articles comparing differences regarding the complications. Methods: We have retrospectively analyzed the medical records and the radiographs of patients older than 18 years who underwent this procedure in our service between 2005 and 2019 through retrograde intramedullary nails or lateral locking plates and compression screws with at least 12 months of follow-up and with no history of osteomyelitis in these bones. Results: We evaluated a total of 67 patients; of these, 48 received retrograde intramedullary nail implants and 19 received locking plates and compression screws. The overall mean age was 48 years; the median follow-up time was 64.3 months. The complication rate was 60.4% for the intramedullary nail procedure and 52.6% for the locking plate combined with compression screws procedure. Conclusion: No significant differences were found in the complication rates between the 2 implants. Level of Evidence: Level V, Case series.

[Comparison of curative effect between percutaneous compression plate and cannulated compression screw in the treatment of displaced femoral neck fractures in young and middle-aged patients].

OBJECTIVE: To compare the efficacy of percutaneous compression plate and cannulated compression screw in the treatment of displaced femoral neck fractures in young and middle-aged patients. METHODS: From January 2015 to July 2020, 68 young and middle-aged patients with displaced femoral neck fracture were retrospectively analyzed. Among them, 31 cases were fixed by percutaneous compression plate (PCCP), and 37 cases were fixed by cannulated compression screw (CCS). General data such as gender, age, cause of injury, comorbidities, fracture classification and cause of injury of two groups were collected. The operation time, intraoperative blood loss, hospital stay, full weight bearing time, fracture healing time, visual analogue scale(VAS), Harris hip score and complications were compared between two groups. RESULTS: Patients in both groups were followed up for more than 2 years. There were no significant differences in operation time, intraoperative blood loss, fracture reduction quality, hospital stay and VAS between two groups. The fracture healing time in PCCP group was significantly shorter than that in CCS group (t=-4.404, P=0.000). The complete weight bearing time of PCCP group was significantly shorter than that of CCS group (t=-9.011, P=0.000). Harris score of hip joint in PCCP group was better than that in CCS group 2 years after operation (P=0.002). Complications occurred in 3 cases (9.68%) in PCCP group, while 11 cases (29.72%) in CCS group, with a statistically significant difference (P=0.042). CONCLUSION: Both PCCP and CCS can be used for the treatment of displaced femoral neck fractures in young and middle-aged people. Compared with CCS, PCCP fixation can achieve shorter fracture healing time and create conditions for early full weight bearing. PCCP results in higher hip score and lower complications.

Double screw versus angular stable plate fixation of scaphoid waist nonunions in combination with intraoperative extracorporeal shockwave therapy (ESWT).

INTRODUCTION: Over the past years, different fixation techniques focused on rotational stability in order to increase stability and stimulate union rates. Additionally, extracorporeal shockwave therapy (ESWT) has gained importance in the treatment of delayed and nonunions. Purpose of this study was to compare the radiological and clinical outcome of two headless compression screws (HCS) and plate fixation in scaphoid nonunions, in combination with intraoperative high energy ESWT. MATERIALS AND METHODS: Thirty-eight patients with scaphoid nonunions were treated by using a nonvascularized bone graft from the iliac crest and stabilization with either two HCS or a volar angular stable scaphoid plate. All patients received one ESWT session with 3000 impulses and energy flux per pulse of 0.41 mJ/mm2 intraoperatively. Clinical assessment included range of motion (ROM), pain according to the Visual Analog Scale (VAS), grip strength, disability of the Arm Shoulder and Hand Score, Patient-Rated Wrist Evaluation Score, Michigan Hand Outcomes Questionnaire and modified Green O'Brien (Mayo) Wrist Score. To confirm union, a CT scan of the wrist was performed. RESULTS: Thirty-two patients returned for clinical and radiological examination. Out of these, 29 (91%) showed bony union. All patients treated with two HCS compared to 16 out of 19 (84%) patients treated by plate showed bony union on the CT scans. The difference was not statistically significant. However, at a mean follow-up interval of 34 months, no significant differences could be found in ROM, pain, grip strength and patient-reported outcome measurements between the two HCS and plate group. Height-to-length ratio and capitolunate angle improved significantly in both groups compared to preoperative. CONCLUSIONS: Scaphoid nonunion stabilization by using two HCS or angular stable volar plate fixation and intraoperative ESWT results in comparable high union rates and good functional outcome. Due to the higher rate for a secondary intervention (plate removal), HCS might be preferable as first choice, whereas the scaphoid plate fixation should be reserved for recalcitrant (substantial bone loss, humpback deformity or failed prior surgical intervention) scaphoid nonunions.

Clinical Results of Surgical Treatment for Comminuted Radial Head and Neck Fracture: Headless Compression Screws Versus Plate Fixation.

Background: We surgically treated comminuted radial head and neck fractures using headless compression screws, including multiple screws for the radial head and a single oblique screw for the radial neck. This study aimed to compare the clinical and radiological results for comminuted radial head and neck fractures between surgery using headless compression screws with a single oblique screw for the radial neck, our new procedure, and a plate system precontoured to the proximal radius. Methods: This retrospective study included 23 patients (11 and 12 in the screw and plate groups, respectively). The fractures were type 3 according to the Mason-Johnston classification modified by Broberg and Morrey. Clinical outcomes analyzed included the motion range of the elbow and forearm, Mayo Elbow Performance Score, and radiological assessments. In addition, postoperative complications were also investigated. The average follow-up was 18 months. Results: The bone union was achieved in all the patients, and there were no significant differences in clinical outcomes and radiological assessments except forearm supination (p = 0.02). Furthermore, additional surgical procedures were performed in one and five patients in the screw and plate groups, respectively (p = 0.16). Posterior nerve palsy was observed in two patients in the plate group. Complications were observed in one and six patients in the screw and plate groups, respectively (p = 0.07). Conclusion: Both surgical procedures achieved good clinical and radiological outcomes with bone and ligament injury repair. The screw group had a greater range of forearm supination than the plate group.

Gamma Nail Combined with One Cannulated Compression Screw Fixation for Treating Pauwels Type III Femoral Neck Fractures in Young and Middle-Aged Adults: Clinical Follow-Up and Biomechanical Studies.

OBJECTIVE: Recently, some clinical studies have reported the use of an intramedullary nailing system for treating unstable femoral neck fractures or femoral neck fractures combined with femoral shaft fractures in young adults, and the results have indicated certain advantages. However, no study has investigated the mechanical properties of this method. We aimed to evaluate the mechanical stability and clinical efficacy of the Gamma nail combined with one cannulated compression screw (CCS) fixation for treating Pauwels type III femoral neck fracture in young and middle-aged adults. METHODS: This study consists of two parts: a clinical retrospective study and randomized controlled biomechanical test. Twelve adult cadaver femora were used to test and compare the biomechanical properties among three fixation methods: three parallel CCS (group A), Gamma nail (group B), and Gamma nail combined with one cannulated compression screw (group C). The single continuous compression test, cyclic load test, and ultimate vertical load test were used to evaluate the biomechanical performance of the three fixation methods. We also conducted a retrospective study of 31 patients with Pauwels type III femoral neck fractures, including 16 patients with fractures fixed with three parallel CCS (CCS group) and 15 patients with fractures fixed with Gamma nail combined with one CCS (Gamma nail + CCS group). The patients were followed up for at least 3 years, and all were evaluated for surgical time (from skin incision to closure), surgical blood loss, hospital stay, and the Harris hip score. RESULTS: In mechanical experiments, we have found that the mechanical advantages of Gamma nail fixation are not as good as those of conventional CCS fixation. However, the mechanical properties of Gamma nail fixation combined with one cannulated screw perpendicular to the fracture line are much better than those of Gamma nail fixation and CCS fixation. No significant difference was found in the incidence of femoral head necrosis and nonunion between the CCS and Gamma nail + CCS groups. Moreover, there was no statistically significant difference in the Harris hip scores between the two groups. One patient in the CCS group showed significant withdrawal of cannulated screws at 5 months after surgery, whereas in the Gamma nail + CCS group, all patients, including those with femoral neck necrosis, showed no loss of stability of the fixation. CONCLUSION: Among the two fixation methods evaluated in this study, Gamma nail combined with one CCS fixation showed better biomechanical properties and may reduce complications associated with unstable fixation devices.

A Biomechanical Comparison of Fixation Techniques in Metacarpal Shaft Fractures.

Background Typically, metacarpal shaft fractures are treated with closed reduction percutaneous pinning, intramedullary nails, or plate fixation. Recently some surgeons have begun using intramedullary headless compression screws. Questions/Purposes The purpose of this study was to compare intramedullary screw fixation to K-wire fixation, which is the standard of care in a transverse metacarpal midshaft fracture, using a cadaveric model. Our hypothesis was that intramedullary screw fixation would have a biomechanical advantage (higher stiffness and peak load to failure) when compared with dual Kirschner wire fixation of transverse metacarpal shaft fractures. Methods Four-point bend testing was performed to compare stiffness and failure load values of seven paired 2nd and 3rd metacarpals instrumented with headless intramedullary compression screw fixation or Kirschner wire fixation. Similar testing was performed on 14 unpaired 4th metacarpals. Results There was no significant difference in peak load ( p = 0.60) or stiffness ( p = 0.85) between fixation groups for the 2nd and 3rd instrumented metacarpals. For the instrumented 4th metacarpals, there was no significant difference in peak load ( p = 0.14), but the stiffness was significantly greater ( p = 0.01) for the compression screw group compared with the Kirschner wire fixation. Conclusions/Clinical Relevance In this study, the load to failure was not different between the two fixation methods and likely both techniques can sustain physiologic loads needed for rehabilitation. The greater stiffness in the 4th metacarpal compression screw group may be related to the smaller canal morphology than in the 2nd and 3rd metacarpals. Larger diameter screws may be needed to obtain a better fit particularly in the 2nd and 3rd metacarpals.

Arthroscopic treatment of unstable scaphoid fracture and nonunion with two headless compression screws and distal radius bone graft.

BACKGROUND: The treatment of unstable scaphoid fracture and nonunion remains a challenging problem for hand surgeons. Minimally invasive treatment has become the preferred method of treatment. PURPOSE: This study introduces the arthroscopic technique with two headless compression screws (HCS) fixation and distal radius bone grafting for the treatment of unstable scaphoid fracture and nonunion, aiming to evaluate its clinical and radiological outcomes. METHODS: It was a retrospective study. From January 2019 to February 2021, a total of 23 patients were included in the current study. Among them, 13 patients with unstable scaphoid fracture underwent arthroscopic treatment with two HCS; 10 patients with scaphoid nonunion underwent arthroscopic treatment with two HCS and a distal radius bone graft. The range of motion of the wrist, visual analog scale (VAS), grip strength, the Modified Mayo Wrist Score (MMWS), the Patient-Rated Wrist Evaluation (PRWE) score, and the Disability of the Arm, Shoulder and Hand (DASH) score were collected at preoperatively and the final follow-up. A computed tomography scan of the wrist was performed on each patient to analyze for union and postoperative osteoarthritis during the follow-up period. RESULTS: Significant improvement was only observed in wrist extension. Clinical outcomes including grip strength, VAS pain score, MMWS, PRWE score, and DASH score were significantly improved at the final follow-up. In the subgroup analysis, both patients stabilized with either two HCS or a distal radius bone graft and two HCS have improved clinical outcomes after surgery, respectively. All patients achieved union. No screw fixation failure occurred, and no other postoperative complication was observed in any of the patients. CONCLUSIONS: The arthroscopic technique with two-HCS fixation and distal radius bone grafting is a reliable and effective technique for the treatment of unstable scaphoid fracture and nonunion, providing satisfactory union rates and clinical outcomes.

The Effect of Buttress Plating on Biomechanical Stability of Coronal Shear Fractures of the Capitellum: A Cadaveric Study.

PURPOSE: The purpose of this study was to compare, using a cadaveric model, the biomechanical properties of headless compression screws (HCSs) and HCSs augmented with a buttress plate (BP) in capitellar fractures. METHODS: Twenty pairs of fresh-frozen humeri (mean age, 46.3 years; range, 33-58 years) were used. The soft tissue was removed, and a Dubberley type IA capitellar fracture was created. One specimen in each pair was randomly assigned to receive either two 2.5-mm HCSs (HCS group) or two 2.5-mm HCSs augmented with an anterior 2.4-mm BP (HCS + BP group). This resulted in a similar distribution of the left and right humeri between the groups. Cyclic loading was performed, and displacement of the capitellum at 50, 100, 250, 500, 1,000, and 2,000 cycles was assessed using a motion capture system. This was followed by load-to-failure testing, wherein the load at a displacement of 1 and 2 mm was recorded. Failure was defined as 2-mm displacement. RESULTS: During cyclic loading, there were no significant differences in the displacement between the HCS and HCS + BP groups at any of the assessed cycles. During load-to-failure testing, no significant strength differences were observed in the load at 1-mm displacement between the HCS (mean: 449.8 N, 95% CI: 283.6-616.0) and HCS + BP groups (mean: 606.2 N, 95% CI: 476.4-736.0). However, a significantly smaller load resulted in a 2-mm displacement of the fragment in the HCS group (mean: 668.8 N, 95% CI: 414.3-923.2) compared with the HCS + BP group (mean: 977.5 N, 95% CI: 794.1-1,161.0). CONCLUSIONS: Anterior, low-profile buttress plating in addition to HCSs results in a significantly higher load to failure compared with HCSs alone in a biomechanical Dubberley type IA capitellar fracture model. CLINICAL RELEVANCE: The addition of an anterior BP may be considered to improve initial stability in select cases such as osteoporotic patients or when the posterolateral column is frail.

Prospective Comparison of the Early Outcomes of Headless Compression Screw and Percutaneous K-Wire Fixation in Metacarpal Fractures.

PURPOSE: The study aimed to assess early clinical outcomes achieved by headless compression screws (HCS) in fixation of metacarpal fractures, and to compare them with outcomes of percutaneous K-wire fixation. The hypothesis was that HCS would show better arc of motion and superior early clinical outcomes. METHODS: This was a randomized study of nonthumb metacarpal neck and shaft fractures. To compare the 2 surgical techniques, 23 patients treated for metacarpal neck and shaft fractures were divided into 2 groups: 11 treated with K-wire fixation and the other 12 with HCS fixation. We followed the patients for 12 weeks. The primary objective was to compare metacarpophalangeal arc of motion, and the secondary aim was to determine clinical union, radiographic union, and recovery time before returning to employment in the 2 groups. RESULTS: At each follow-up visit, patients in the group treated with HCS had better metacarpophalangeal arc of motion than those treated with K-wire fixation. The HCS group showed a shorter time interval to return to work (at 3 weeks) and no complications, while the K-wire group had 1 pin track infection, which was treated with oral antibiotics and pin removal. CONCLUSIONS: Compared with K-wire fixation, limited-open HCS fixation for metacarpal neck and shaft fractures was superior in terms of the early postoperative metacarpophalangeal arc of motion and return to work. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.