Epidemiology and management of proximal tibia fractures in children and adolescents: a population-based study based on the Kids' Fracture Tool.

BACKGROUND AND PURPOSE: Proximal tibial fractures are infrequent injuries in children, and the literature on epidemiology, associated injuries, and management is limited. We calculated a population-based incidence and described the characteristics of proximal tibial fractures in children in terms of complications and management. PATIENTS AND METHODS: This is a retrospective study over a 6-year-period during including 241 children with proximal tibial fractures who presented to our university hospital. Demographic and fracture-related data was collected from the Kids' Fracture Tool. The number of children during the study period was collected from statistical yearbooks of the City of Helsinki to estimate annual incidence. RESULTS: Extra-articular fractures (129/241) peaked at the age of 3 and tibial tubercle (42/241) and intra-articular fractures (70/241) peaked at the age of 15. Annual incidences were estimated to be 3.4/100,000 children and 22/100,000 children in the age group of 13-16 years for ACL avulsions, and 3.8/100,000 children and 21/100,000 children in the age group of 13-16 years for tibial tubercle fractures. The incidence of vascular compromise (0%) and compartment syndrome was low (0.4 %, 1/241). CONCLUSION: Proximal tibial fractures present with a bimodal distribution, with extra-articular fractures peaking at the age of 3 years and fractures of the tibial tuberosity and intra-articular fractures peaking at the age of 15 years. Additionally, associated compartment syndrome and vascular compromise was not as common as previously reported.

Minimum 5-Year Outcomes of Osteochondral Autograft Transplantation with a Concomitant High Tibial Osteotomy for Spontaneous Osteonecrosis of the Knee with a Large Lesion.

OBJECTIVE: The purpose of this study was to evaluate the mid-term clinical outcomes of osteochondral autograft transplantation (OAT) with concomitant high tibial osteotomy (HTO) in spontaneous osteonecrosis of the knee (SONK) with a large lesion. DESIGN: A total of 48 knees of 48 consecutive patients with SONK (lesion size ≥4 cm2, no age criteria) who underwent opening wedge HTO and concomitant OAT were retrospectively investigated, and those who were followed up postoperatively for at least 5 years were included in this case series study. Clinical outcomes were evaluated using knee and function scores of Knee Society Score, radiographic outcomes were evaluated using the anatomical femorotibial angle (FTA), and these outcomes were compared between patients aged ≥70 years and <70 years. RESULTS: Of the 48 cases, a total of 43 cases were available for review at a minimum of 5 years, and 5 cases were excluded from the analysis. Overall, the mean knee score improved from preoperative 48.8 ± 13.3 to postoperative 87.9 ± 8.6 at 1 year (P < 0.05) and 85.0 ± 10.4 at final follow-up (P < 0.05 vs. preop., N.S. vs. 1 year). The mean function score also improved from preoperative 60.1 ± 10.9 to postoperative 87.3 ± 12.2 at 1 year (P < 0.05) and 84.2 ± 12.4 at final follow-up (P < 0.05 vs. preop., N.S. vs. 1 year). The mean standing FTA was corrected significantly from 181.1° ± 2.7° preoperatively to 169.7° ± 2.4° at 1 year (P < 0.05) and 169.4° ± 3.1° at final follow-up (P < 0.05 vs. preop., N.S. vs. 1 year). There were no significant differences in clinical and radiographic outcomes between patients aged ≥70 years and <70 years. There were 4 cases of lateral hinge fracture around the osteotomy site and 1 case of delayed union. None of the patients underwent revision surgery during the follow-up period (survival rate of 100%). CONCLUSIONS: Mid-term clinical outcomes of patients with SONK who underwent HTO and OAT with a relatively large lesion were good.

Surgeon case volume and the risk of complications following surgeries of displaced intra-articular calcaneal fracture.

PURPOSE: This study aimed to address the relationship between surgeon volume and the risk of complications following surgeries of displaced intra-articular calcaneal fractures (DIACFs). METHODS: We retrospectively reviewed the medical records and the follow-up registers for patients who underwent open reduction and internal fixation with plate/screws in our center between January 2015 and June 2020. Surgeon volume was defined as the number of surgically treated calcaneal fractures within the past 12 months, and was dichotomized on basis of the optimal cut-off value. The outcome measure was the documented overall complications within 1 year after surgery. Four logistics regression models were constructed to examine the potential relationship between surgeon volume and complications. RESULTS: Among 585 patients, 49 had documented complications, representing an overall rate of 8.4%. The overall complication rate was 20.0% (22/111) in patients operated on by the low-volume surgeons and 5.7% (27/474) by the high-volume surgeons, with a significant difference (p < 0.001). The 4 multivariate analyses showed steady and robust inverse volume-complication relationship, with OR ranging from 3.8 to 4.4. The restricted cubic splines adjusted for total covariates showed the non-linear fitting "L-shape" or "reverse J-shape" curve (p = 0.041), and the OR was reduced until 10 cases, beyond which the curve leveled. CONCLUSIONS: Our findings reflected the important role of maintaining necessary operative cases, potentially informing optimized surgical care management.

Implant Charge Differences Between Distal Radius Fixation Constructs (CPT 25607, 25608, and 25609).

BACKGROUND: Implants are a significant contributor to health care costs. We hypothesized that extra-articular fracture patterns would have a lower implant charge than intra-articular fractures and aimed to determine risk factors for increased cost. METHODS: In total, 163 patients undergoing outpatient distal radius fracture fixation at 2 hospitals were retrospectively reviewed stratified by Current Procedural Terminology codes. Implants and associated charges were noted, as were sex, age, insurance status, surgeon specialty, and location. Bivariate and multivariable regression were used to determine associations. RESULTS: Total implant charges were significantly lower for 25607 (extraarticular, $3,348) than 25608 (2-part intraarticular, $3,859) and 25609 (3+ part intraarticular, $3,991). In addition, intra-articular fractures had higher charges for distal screws/pegs and bone graft. Charge was lower when surgery was performed at a trauma center. There was no charge difference associated with insurance status, age, sex, hand surgery specialty, or fellow status. Substantial intersurgeon variation existed in all fracture types. CONCLUSION: Distal radius fractures may represent a good model for examining implant costs. Extra-articular fractures had lower implant charges than intra-articular fractures. These data may be used to help construct pricing for distal radius fracture bundles and potential cost savings.

Surgical treatment for posteromedial talar process fractures.

PURPOSE: The first descriptions on medial talar tubercle fractures are attributed to Cedell. He described avulsion fractures of the insertion of the posterior talotibial ligament. However the true etiology has not been established. Since little is known about these fractures, they are easily misdiagnosed as simple ankle sprains. Untreated, these fractures may lead to chronic ankle pain. To improve the understanding of the etiology and outcome of these fractures a systematic review was conducted of all cases of isolated fractures of the medial tubercle of the posterior talar process. In addition we present the first series of competitive athletes treated by means of the two-portal hindfoot approach for isolated medial talar tubercle fractures. METHODS: A systematic search was performed to identify all cases of medial tubercle fractures. Data on trauma mechanism, clinical presentation, imaging and treatment were extracted. In addition we retrospectively report on the results of endoscopically treated patients in our institution over the last fifteen years. Of all patients Numeric Rating Scores (NRS) for Satisfaction, Pain and Function, Foot Ankle Outcome Scores (FAOS), return to sport and complications were reported. RESULTS: Eightteen articles were included reporting on 33 patients with an isolated fracture or avulsion of the posteromedial talar process. Most of the fractures occurred during sport activities (58%), followed by motor vehicle accidents (21%) and fall from height (12%). Of the activities during sport, 73% resulted following an ankle sprain. Reasonable to good outcomes are described in cases treated with immobilization, open reduction internal fixation or open excision. Of the nine patients treated in our institution, five were male and the median age was 29. All were participating in sports at a competitive level, with four of them being a professional athlete. In most patients the diagnosis was made more than a year after initial trauma. Ankle sprain was most common trauma mechanism. In some patients it was evident the avulsion was part or the deep portion of the deltoid ligament, however in two cases it was more likely an avulsion of the flexor hallucis longus (FHL) retinaculum. The median follow-up was 69 months (IQR 12.0-94.3). At final follow-up patients had little pain, NRS 1. Median NRS for satisfaction and function were 7 and 8, respectively. All patients did resume sport activities, however only four reached the preinjury level. Of the five patients that did not return to their pre-injury level of activity, two were professional athletes at the end of their career, and retired not due to ankle complaints. One complication was reported. CONCLUSION: Fractures of the medial tubercle are rare and based on the available literature there is not one distinct trauma mechanism. Based on literature no recommendation for treatment can be made. Our results show endoscopic excision of the fragment as a save alternative for open surgical treatment.

Osteochondritis Dissecans of the Knee: Short-Term Outcomes of a Hybrid Technique to Restore a Partially Salvageable Progeny Fragment.

OBJECTIVE: This retrospective case series describes a hybrid fixation technique and determines the clinical outcomes, knee function, and activity level of patients at short-term follow-up. DESIGN: Seventeen patients (18 knees) with unstable osteochondritis dissecans (OCD) lesions involving the knee were treated with a hybrid fixation technique in which the salvageable fragment was fixed and osteochondral autograft transplantation system (OATS) was used for the unsalvageable fragment. Thirteen lesions involved the medial femoral condyle, 4 involved the lateral femoral condyle, and 1 involved the patella. Mean patient age was 17 years (range 12-28 years). All lesions were International Cartilage Repair Society (ICRS) grade III or IV. The patients were prospectively followed postoperatively. Outcome measures included the International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and the Tegner activity scale. RESULTS: At mean follow-up of 36 months (range 24-67.2 months), the mean postoperative KOOS scores, given as mean (SD), were as follows: Quality of Life (QoL) 91.1 (17.0), Activities of Daily Living (ADL) 99.5 (1.5), Sport 94.5 (11.2), Pain 97.4 (5.8), and Symptoms 95.9 (6.5). Mean IKDC score was 96.2 (7.0). There was no significant difference between mean preinjury (7.95, SD = 1.1) and mean postoperative (7.45, SD = 1.5) Tegner scores (P = 0.363). The mean Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score was 87.5 at a mean 7.8 months (range 3-18 months) postoperation. There were no reported complications. CONCLUSION: The results of this case series suggest that patients with partially salvageable OCD lesions involving the knee can have positive short-term outcomes and can expect a low complication rate when treated with a hybrid technique of fixation with osteochondral autograft transfer.

Comparative Analysis of Mechanism-Associated 3-Dimensional Tibial Plateau Fracture Patterns.

BACKGROUND: The association between tibial plateau fracture morphology and injury force mechanism has not been well described. The aim of this study was to characterize 3-dimensional fracture patterns associated with hypothesized injury force mechanisms. METHODS: Tibial plateau fractures treated in a large trauma center were retrospectively reviewed. Three experienced surgeons divided fractures independently into 6 groups associated with injury force mechanisms proposed from an analysis of computed tomographic (CT) imaging: flexion varus, extension varus, hyperextension varus, flexion valgus, extension valgus, and hyperextension valgus. The fracture lines and comminution zones of each fracture were graphically superimposed onto a 3-dimensional template of the proximal part of the tibia. Fracture characteristics were then summarized on the basis of the fracture maps. The association between injury force mechanism and ligament avulsions was calculated. RESULTS: In total, 353 tibial plateau fractures were included. The flexion varus type pattern was seen in 67 fractures characterized by a primary fracture apex located posteromedially and was frequently associated with concomitant anterior cruciate ligament (ACL) avulsion (44.8%). The extension varus pattern was noted in 60 fractures with a characteristic medial fragment apex at the posteromedial crest or multiple apices symmetrically around the crest and was commonly completely articular in nature (65%). The hyperextension varus pattern was seen in 47 fractures as noted by anteromedial articular impaction, 51% with a fibular avulsion and 60% with posterior tension failure fragments. The flexion valgus pattern was observed in 51 fractures characterized by articular depression posterolaterally, often (58.9%) with severe comminution of the posterolateral cortical rim. The extension valgus patterns in 116 fractures only involved the lateral plateau, with central articular depression and/or a pure split. The hyperextension valgus pattern occurred in 12 fractures denoted by anterolateral articular depression. A moderate positive association was found between flexion varus fractures and ACL avulsions and between hyperextension varus fractures and fibular avulsions. CONCLUSIONS: Tibial plateau fractures demonstrate distinct, mechanism-associated 3-dimensional pattern characteristics. Further research is needed to validate the classification reliability among other surgeons and to determine the potential value in the diagnosis and formulation of surgical protocols.

Clinical Outcomes of Revision Osteochondral Allograft Transplantation.

PURPOSE: To assess the survivorship, clinical outcomes, and radiographic outcomes of patients who have undergone revision osteochondral allograft (OCA) to the knee in a retrospective case series. METHODS: Nine patients who underwent revision OCA by the senior author between January 2003 and December 2015 with a minimum follow up of 2 years were reviewed retrospectively. Patients completed patient-reported outcome surveys containing the visual analog scale, the International Knee Documentation Committee, the Knee injury and Osteoarthritis Outcome Score, Lysholm score, and the Short-Form 12. Radiographic analysis included anteroposterior view graded via the Kellgren and Lawrence scale. Complications and reoperations were analyzed, with failure defined as conversion to arthroplasty. (Institutional review board 15050301.) RESULTS: One of 10 consecutive patients was lost to follow up, for an overall follow-up rate of 90% (5 males, 4 females); mean follow up, 4.53 ± 3.17 years. The median patient age at the time of revision OCA was 33 years (interquartile range [IQR], 8.6), the median defect size was 4.0 cm2 (IQR, 0), and the median time from index OCA to revision OCA was 2.9 years (IQR, 1.9). Five patients (50%) underwent subsequent surgery at a median of 1.92 years (IQR, 7.25), with 1 progressing to arthroplasty at 23 months after revision OCA, for an overall failure rate of 11%. There were no significant differences in any of the patient-reported outcome assessments compared with prerevision OCA (postindex OCA) values at final follow up (P > .05 for all). Similarly, there were no significant differences in Kellgren and Lawrence score before and after surgery (P = .1). CONCLUSIONS: At a mean 4.5 years following revision OCA, there was an 89% graft survivorship rate in a series of 9 patients, with no statistical changes in the radiographic progression of arthritis. LEVEL OF EVIDENCE: Level IV, case series.

Prevention of post-traumatic osteoarthritis after intra-articular knee fractures using hyaluronic acid: a randomized prospective pilot study.

PURPOSE: Based on the irreversible destruction of hyaline cartilage, post-traumatic osteoarthritis (PTOA) is a notorious sequelae after intra-articular knee fractures. This study evaluates the clinical efficacy and applicability of immediate post-operative intra-articular injection of hyaluronic acid (IA HA) into the knee joint with an intra-articular fracture. METHODS: Prospective randomized case-control study involving 40 patients (20 in each group) with intra-articular knee fracture with an average follow-up of 23 months (range 18-24 months). Twenty patients with intra-articular distal femoral or intra-articular proximal tibial fractures who met our inclusion criteria received three intra-articular hyaluronic acid injections weekly starting immediately after ORIF. Another 20 patients serving as a control group received no injection after ORIF. Patients were assessed functionally with Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) score. Plain X-rays and when indicated CT scans were used to assess radiological union. RESULTS: The results showed patients treated with intra-articular hyaluronic acid injection after fixation had significantly less pain (KOOS) (p = 0.01). No significant difference was found between both groups in other KOOS-related outcome measures, complications, functional outcome, or quality of life. CONCLUSIONS: These preliminary results support a direct role for hyaluronic acid in the acute phase of the inflammatory process that follows articular injury and provides initial evidence for the efficacy of IA HA.

Proximal radius fracture morphology following axial force impact: a biomechanical evaluation of fracture patterns.

BACKGROUND: The most common location for articular fractures of the radial head is often reported to be the anterior lateral aspect of the radial head with the arm in neutral position. However, these findings mainly base on clinical observations rather than precise biomechanical measurements. The purpose of this study was to evaluate the formation of proximal radius fractures, the association between axial forces and fracture morphology, energy to failure and bone stiffness in a biomechanical in-vitro setup. METHODS: 18 fresh-frozen cadaveric radii performed axial load compression with 10 mm/min loading until bone failure. Energy to failure and bone stiffness were recorded. Proximal radial head fracture morphology and affection of the anterolateral quadrant were optically analyzed. RESULTS: All radii survived a compression load of 500 N. The mean compressive forces that lead to failure were 2,56 kN (range 1,30 - 7,32). The mean stiffness was 3,5 kN/mm (range 2,0 - 4,9). 11 radial neck fractures and 7 radial neck and radial head multifragment fractures were documented. The anterolateral quadrant was involved in 78% of tested radii. CONCLUSION: The anterolateral quadrant of the radial head (in neutral position of the forearm) is confirmed to be the most common location for articular radial head fractures in a biomechanical setting. In case of a fall on the outstretched arm radial neck fractures should be securely ruled out due to prior occurrence to radial neck and head fractures.

Low-Energy Lisfranc Injuries in an Athletic Population: A Comprehensive Review of the Literature and the Role of Minimally Invasive Techniques in Their Management.

Tarsometatarsal (TMT) joint complex injuries can be caused by either direct or indirect injuries. The Lisfranc joint represents approximately 0.2% of all fractures. Up to 20% of these injuries are misdiagnosed or missed on initial radiographic assessment; therefore, a high index of suspicion is needed to accurately diagnose TMT joint injuries and avoid the late sequelae of substantial midfoot arthrosis, pain, decreased function, and loss of quality of life. This review discusses the anatomy, diagnosis, and management of athletic Lisfranc injuries, including a description of the preferred minimally invasive surgical techniques used by the senior author of this article.

Topographic Matching of Osteochondral Allograft Transplantation Using Lateral Femoral Condyle for the Treatment of Medial Femoral Condyle Lesions: A Computer-Simulated Model Study.

PURPOSE: The purpose of this study was to determine whether lateral femoral condyle (LFC) osteochondral allografts (OCAs) would have a similar articular cartilage contour and resulting subchondral bone contour when compared with medial femoral condyle (MFC) allografts for the treatment of MFC chondral defects. METHODS: In this controlled laboratory study, human femoral hemi-condyles (10 MFCs and 8 LFCs) were divided into 4 groups: MFC recipient, MFC donor, ipsilateral LFC donor, and contralateral LFC donor. Computed tomography (CT) images were obtained for each, and 3D CT models were created and exported into point-cloud models. Three circular defect and graft models were created on each condyle at 3 locations (0°, 45° posterior, and 90° posterior regions). The graft model in each donor group was virtually placed on the MFC recipient defect model. The least distances of the articular cartilage surface between the graft and the defect models and the resulting mean least distance of the subchondral bone surface were calculated. RESULTS: The mean least distance of the articular cartilage surface was less than 0.5 mm in all donor-recipients, and there was no significant difference among donor groups. Although the mean least distance of the subchondral bone surface was significantly greater than the articular cartilage surface in all donor groups (P < .001), there was no significant difference among donor groups. CONCLUSION: Ipsilateral and contralateral LFC grafts provided similar articular cartilage surface and resulting subchondral bone surface matching with that of MFC grafts, suggesting that LFCs could be a potential source of OCA for the treatment of MFC lesions. CLINICAL RELEVANCE: Ipsilateral and contralateral LFCs can be suitable donor sites for the treatment of MFC lesions with OCAs.

Pisiform malalignment associated with distal radius fractures.

BACKGROUND: The association of scaphoid or other carpal bone fractures with distal radius fractures is frequently reported, whereas few studies have described pisiform malalignment associated with distal radius fractures. The purpose of this study was to investigate the frequency and characteristics of pisiform malalignment associated with distal radius fractures. METHODS: We performed a retrospective study by reviewing the data of 152 consecutive patients with a mean age of 63 years who were treated surgically for distal radius fractures during a five-year period. We evaluated the pisotriquetral joint via preoperative sagittal computed tomography (CT) and assessed pisiform malalignment. Pisiform malalignment was defined as follows: (1) wide type, joint space ≥4.0 mm; (2) non-parallel type, loss of parallelism of the joint surface of ≥20°; or (3) overriding type, proximal or distal overriding of the pisotriquetral joint ≥2.0 mm. We investigated the relationship between pisiform malalignment and the patterns of distal radius fractures. Pisiform malalignment was assessed using postoperative CT to determine whether it had been reduced. RESULTS: Pisiform malalignment was observed in 48 cases involving 44 patients with a mean age of 58 (17-81) years. The patients included 16, 17, and 15 cases of the wide type, non-parallel type, and overriding type, respectively. Distal radius fractures with dorsal displacement exhibited pisiform malalignment significantly more frequently than those with volar displacement. No significant difference was noted between intra- and extra-articular fractures or between patients with and without distal ulnar fractures. Among the 22 pisiform malalignment cases assessed via postoperative CT, 15 cases were reduced, and 7 cases remained malaligned. The non-parallel type exhibited the lowest reduction rate among the 3 types. CONCLUSIONS: Among distal radius fractures, 29% were complicated by pisiform malalignment. Distal radius fractures with dorsal displacement exhibited a significantly increased frequency of pisiform malalignment compared to those with volar displacement.

Osteochondral Injuries of the Knee in Pediatric Patients.

Osteochondral injuries in pediatric patients may occur as a result of a traumatic injury or secondary to an osteochondritis dissecans (OCD) lesion. Lateral patella dislocation is a common traumatic cause of osteochondral injury that typically occurs at the medial facet of the patella or at the lateral aspect of the distal femur. Multiple theories have been proposed for the cause of an OCD lesion in the knee, including trauma or repetitive microtrauma, local vascular insufficiency, and family history. The most "classic" location for OCD lesions of the knee is the lateral aspect of the medial femoral condyle of the distal femur. Multiple treatment options are available for both traumatic osteochondral injuries and OCD lesions, with important determining factors of treatment being skeletal maturity of the patient, instability of the fragment, lesion location, and size of the lesion. Nonsurgical management is appropriate in some situations. Surgical options range from simple fragment excision to internal fixation of the fracture fragment to more complex cartilage restoration or replacement procedures. This special focus section will discuss the diagnosis and treatment options for traumatic osteochondral knee injuries, including the subset secondary to juvenile OCD lesions.

Diagnostic Value of Computed Tomography and Risk Factors for Lateral Hinge Fracture in the Open Wedge High Tibial Osteotomy.

PURPOSE: The purposes of this study were to evaluate (1) the disparity of detection of lateral hinge fracture (LHF) between postoperative simple radiography and high-resolution computed tomography (CT) and affecting factors of LHF and (2) whether generally recommended postoperative rehabilitation protocols are appropriate according to the type of LHF. METHODS: From 2014 to 2015, patients who underwent primary open wedge high tibial osteotomy (OWHTO) for isolated medial compartment osteoarthritis of the knee joint were retrospectively enrolled. The patients with minimum 1-year follow-up were included. The incidence of LHF after OWHTO based on simple radiographs was compared with its incidence based on CT scans. In the stable type of LHF and the non-LHF group, early weight bearing was encouraged immediately after OWHTO. In unstable LHF (types II and III), weight bearing was delayed until 2 weeks postoperatively. RESULTS: Twenty-three cases (24.5%) of LHF after 94 OWHTOs were detected (15 cases on simple radiographs, 8 cases on CT scan). The coronal osteotomy slope and the osteotomy gap were significantly larger in the LHF group than in the non-LHF group (coronal osteotomy slope, 20.3° ± 5.1° vs 16.7° ± 4.2°, P = .001; anterior osteotomy gap, 7.9 mm ± 2.1 mm vs 6.7 mm ± 1.8 mm, P = .008; posterior osteotomy gap, 12.7 mm ± 3.7 mm vs 11.2 mm ± 3.2 mm, P = .048). The correction loss of the hip-knee-ankle angle and the medial proximal tibial angle in the LHF group was significantly larger than those in the non-LHF group (1.3° ± 1.8° vs 0.4° ± 1.4°, P < .001; 1.3° ± 1.1° vs 0.7° ± 0.9°, P = .009, respectively). CONCLUSIONS: Further evaluation with CT scanning is highly valuable immediately after all OWHTO because of its higher detection rate (24.5%) of LHF compared with simple radiographs (16%). In addition, the coronal osteotomy slope was steeper and the opening gap was larger in the LHF group than in the non-LHF group. Finally, the LHF should be managed conservatively in order to prevent postoperative correction loss. LEVEL OF EVIDENCE: Level III, case-control study.

Mallet Fractures of the Thumb Compared With Mallet Fractures of the Fingers.

BACKGROUND: The purpose of this study was to look for differences in mechanism, radiographic findings, and treatment between mallet fractures of the thumb and mallet fractures of the index through small fingers. METHODS: This retrospective study included 24 mallet fractures of the thumb and 392 mallet fractures of other digits. We compared demographics, injury factors (side, dominant hand, time between injury and first visit, and injury mechanism), subluxation, fragment size, treatment, and time from injury to final evaluation between the 2 groups. RESULTS: Mallet fractures of the thumb presented for treatment sooner after injury (2.9 vs 13 days on average), had less fragment displacement (27% vs 33%), and less articular involvement (39% vs 46% on average). None of the mallet fractures of the thumb had radiographic evidence of subluxation, whereas 25% of mallet fractures of other fingers had initial or later subluxation. CONCLUSIONS: Mallet fractures of the thumb are not likely to subluxate.

Distal radius fractures-Design of locking mechanism in plate system and recent surgical procedures.

Recently, many studies have emphasized the importance of the comprehension of detailed functional anatomy of the distal forearm and wrist joint, and their biomechanics. A significant contribution which yields good functional outcomes of surgical treatment was the development of the locking plate technology; this technology has facilitated the improvement of the surgical technique for the fixation of fractures. This article reviews the locking mechanism and design of the fixation screws and plate, and the details of the surgical technique including the double-tired subchondral support procedure as it is applied to common fractures. Arthroscopic-assisted surgical procedures can be used to reduce the intra-articular fracture fragments after realignment of the distal radius with the locking plate. This technique is also useful at the time of fixation to assess soft tissue injury. The combination of arthroscopic-assisted reduction and locking plate fixation is now indicated for AO type C2 and C3 intra-articular comminuted fractures.