Reconstructive surgery after distal fibular resection due to bone tumors: a technical report on surgical strategies and results from the PROSPERO international register of systematic reviews.

Purpose: Primary bone tumors of the fibula are rare. Distal fibular resection has a significant impact on ankle biomechanics and gait, possibly leading to complications such as ankle instability, valgus deformity, and degenerative changes. Question: Is there a need for reconstructive surgery after distal fibular resection, and what reconstructive procedures are available? Materials and methods: The review is registered with the PROSPERO International Register of Systematic Reviews. Inclusion criteria consisted of all levels of evidence, human studies, patients of all ages and genders, publication in English, and resection of the distal portion of the fibula due to tumor pathology. The reviewers defined four different categories of interest by method of treatment. Additional articles of interest during full-text review were also added. Results: The initial search resulted with a total of 2958 records. After screening, a total of 50 articles were included in the study. Articles were divided into 'No reconstruction', 'Soft tissue reconstruction', 'Bone and soft tissue reconstruction', and 'Arthrodesis, arthroplasty or other reconstruction options' groups. Conclusion: Limb salvage surgery should be followed by reconstruction in order to avoid complications. Soft tissue reconstructions should always be considered to stabilize the joint after fibular resection. Bone reconstruction with reversed vascularized fibula is the preferred technique in young patients and in cases of bone defects more than 3 cm, while arthrodesis should be considered in adult patients. Whenever possible for oncologic reason, if a residual peroneal malleolus could be preserved, we prefer augmentation with a sliding ipsilateral fibular graft.

Distinctiveness of Femoral and Acetabular Mesenchymal Stem and Progenitor Populations in Patients with Primary and Secondary Hip Osteoarthritis Due to Developmental Dysplasia.

Primary hip osteoarthritis (pOA) develops without an apparent underlying reason, whereas secondary osteoarthritis arises due to a known cause, such as developmental dysplasia of the hips (DDH-OA). DDH-OA patients undergo total hip arthroplasty at a much younger age than pOA patients (50.58 vs. 65 years in this study). Recently, mesenchymal stem and progenitor cells (MSPCs) have been investigated for the treatment of osteoarthritis due to their immunomodulatory and regenerative potential. This study identified cells in subchondral bone expressing common MSPC markers (CD10, CD73, CD140b, CD146, CD164, CD271, GD2, PDPN) in vivo and compared the proportions of these populations in pOA vs. DDH-OA, further correlating them with clinical, demographic, and morphological characteristics. The differences in subchondral morphology and proportions of non-hematopoietic cells expressing MSPC markers were noted depending on OA type and skeletal location. Bone sclerosis was more prominent in the pOA acetabulum (Ac) in comparison to the DDH-OA Ac and in the pOA Ac compared to the pOA femoral head (Fh). Immunophenotyping indicated diagnosis-specific differences, such as a higher proportion of CD164+ cells and their subsets in DDH-OA, while pOA contained a significantly higher proportion of CD10+ and GD2+ cells and subsets, with CD271+ being marginally higher. Location-specific differences showed that CD271+ cells were more abundant in the Fh compared to the Ac in DDH-OA patients. Furthermore, immunohistochemical characterization of stromal bone-adjacent cells expressing MSPC markers (CD10, CD164, CD271, GD2) in the Ac and Fh compartments was performed. This research proved that immunophenotype profiles and morphological changes are both location- and disease-specific. Furthermore, it provided potentially effective targets for therapeutic strategies. Future research should analyze the differentiation potential of subsets identified in this study. After proper characterization, they can be selectively targeted, thus enhancing personalized medicine approaches in joint disease management.

Specificities in the Structure of the Cartilage of Patients with Advanced Stages of Developmental Dysplasia of the Hip.

Developmental dysplasia of the hip (DDH) presents varying degrees of femoral head dislocation, with severe cases leading to the formation of a new articular surface on the external side of the iliac bone-the neoacetabulum. Despite conventional understanding suggesting otherwise, a tissue resembling hyaline cartilage is found in the neoacetabulum and acetabulum of Crowe III and IV patients, indicating a potential for hyaline cartilage development without mechanical pressure. To test this theory, acetabular and femoral head cartilage obtained from patients with DDH was stained with hematoxylin-eosin and toluidine blue. The immunohistochemical analysis for collagen types II and VI and aggrecan was performed, as well as delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) analysis on a 7.0 T micro-MRI machine. The results obtained from DDH patients were compared to those of the control groups. Hyaline cartilage was found in the neoacetabulum and the acetabulum of patients with DDH. The nature of the tissue was confirmed with both the histological and the MRI analyses. The results of this study proved the presence of hyaline cartilage in patients with DDH at anatomical regions genetically predisposed to be bone tissue and at regions that are not subjected to mechanical stress. This is the first time that the neoacetabular cartilage of patients with advanced stages of DDH has been characterized in detail.

Plantaris tendon is valuable graft for the medial patellofemoral ligament reconstruction: A biomechanical study.

BACKGROUND: Medial patellofemoral ligament (MPFL) reconstruction is a standard treatment option for selected patients with patellar instability. Although frequently performed, the optimal graft source for the procedure has not yet been established. This study aimed to determine whether a two-strand plantaris tendon construct possesses the biomechanical properties needed to act as an MPFL reconstruction graft. METHODS: Thirty paired plantaris and gracilis tendons were harvested from 15 cadavers, mean age at death of 42.7 years. All specimens were frozen and maintained at -20 °C until biomechanical testing. Prior to mechanical testing, specimens were thawed at room temperature. The two-strand plantaris tendon and two-strand gracilis tendon constructs were created and secured in a uniaxial tensile testing machine in a triangular-shaped mode. Biomechanical properties for tensile testing to failure were determined using validated method. Results obtained were compared with the previously published data on native MPFL biomechanical properties. RESULTS: The mean maximal force was 220.3 ± 108.1 N and 448.1 ± 117 N for the two-strand plantaris tendon construct and two-strand gracilis tendon construct, respectively. Significant differences were observed between all biomechanical properties of two-strand plantaris tendon and two-strand gracilis tendon constructs. The mean maximal force of a two-strand plantaris tendon construct and a two-strand gracilis tendon construct were greater than the mean maximal force of the native MPFL reported in all previous studies. CONCLUSIONS: This study suggests that, due to its biomechanical properties, the two-strand plantaris tendon graft is suitable as a graft for MPFL reconstruction.

IMPACT OF CEMENTLESS ZWEYMÜLLER STEM ANTEVERSION ON RESISTANCE TO PERIPROSTHETIC FRACTURE IN TOTAL HIP ARTHROPLASTY.

Total hip arthroplasty implies proper orientation of both acetabular and femoral components with a range of 25-40° of combined anteversion. The aim of the study was to examine resistance to periprosthetic fracture of the axially loaded cross section rectangular femoral stem (Zweymüller) with respect to different degrees of anteversion, implanted in the artificial bone model, in laboratory conditions. Femoral bone models with implanted femoral stems were divided into 3 groups depending on the degree of stem anteversion (A, control group 13-17°; B, stem retroverted 0°-4°; and C, stem anteverted 26-30°). The amount of axial load leading to periprosthetic fracture (PPFx) of the artificial bone model was determined experimentally for each construct. The results showed that the load at which the PPFx occurred significantly increased with the increase of the endoprosthesis anteversion angle. In our clinical practice, we are often unable to place the acetabular component in an ideal grade of anteversion for intraoperatively determined reasons. The results of this experimental study suggested that increasing rectangular femoral (Zweymüller) stem anteversion lowered the risk of PPFx. This study was limited by experimental design (laboratory conditions, artificial bone) and should be clinically verified.

Novel micro-MRI approach for subchondral trabecular bone analysis in patients with hip osteoarthritis is comparable to micro-CT approach.

AIM: To test the agreement between a newly developed micro-magnetic resonance imaging (MRI) analysis of the subchondral bone and the micro-computed tomography (CT) approach. METHODS: Samples obtained from 10 patients with osteoarthritis undergoing total hip arthroplasty were scanned with a 7.0 T micro-MRI. Proton density-weighted images and proton density-weighted images with fat suppression were obtained. The results were validated with a micro-CT device. Micro-MRI and micro-CT scans of the same sample were aligned, and regions of interest were delineated on equal areas of the sample. Bone volume fraction was calculated by using in-house plugins. The agreement between the methods was tested with Bland-Altman analysis. RESULTS: The agreement between the methods was good, with average difference of 2.167%. The differences between the methods were not significant (P=0.272, t test). CONCLUSION: The novel micro-MRI approach could be used for subchondral bone analysis. With further optimization for clinical MRI machines, the approach can be also used in the diagnostics of hip osteoarthritis.

Current knowledge on the genetic background of developmental dysplasia of the hip and the histomorphological status of the cartilage.

Developmental dysplasia of the hip (DDH) represents a morphological abnormality characterized by the incongruity of femoral head and acetabulum. It ranges from mild dysplastic changes to complete dislocation. DDH has been associated with several hereditary and environmental risk factors, which could explain the incidence variability among different countries. Numerous genes may be involved in the disease etiology and progression. However, there are controversies in the literature regarding some of these genes. DDH-induced secondary osteoarthritis (OA) is characterized by changes in the macromolecule content of the cartilage and the expression of cartilage degradation markers. In addition, it exhibits a pattern of specific histological changes, with several reported differences between primary and DDH-induced secondary OA. The articular cartilage of patients with DDH shows specific radiological characteristics, including changes visible already in infancy, but also at pre-arthritic stages, early stages of OA, and in fully developed DDH-induced secondary OA. Although DDH has been extensively researched in different disease stages, the etiology of the disorder still remains uncertain. This review focuses on the current knowledge on the histomorphological status of the cartilage and the genetic background of DDH.

Risk factors for subsidence of modular fluted tapered stem implanted by using transfemoral Wagner approach during revision hip arthroplasty.

PURPOSE: To determine clinical and radiographic risk factors for the vertical subsidence of modular fluted tapered stems implanted using the transfemoral Wagner approach in a cohort of revision hip arthroplasties. METHODS: A retrospective review of a single-centre surgical registry was performed. Patients who underwent a revision total hip arthroplasty, in which the uncemented modular fluted tapered stem (REVISION Hip/Anca-Ti6Al4V, LimaCorporate, Udine, Italy) was implanted using the transfemoral Wagner approach, were identified. Patient's demographic data, clinical and radiographic outcomes and post-operative complications were assessed. As a significant subsidence, a 5-mm cut-off was chosen. RESULTS: We identified 278 revision hip arthroplasties with a mean follow-up of 35 months. The median of subsidence in the group of 5 mm and less was 2 mm, and 17 mm in the group of subsidence of 5 mm and more. A negative correlation was found between the stem subsidence and the length of good contact between the medial and lateral cortical bone and the stem (medial, - 0.248; P < 0.001, lateral, 0.284; P < 0.001). For 200 mm stems, the percentage of good contact between femoral parts of stem and bone on medial side was 40.5% (81.0 mm) for patients with subsidence of five or less mm, and 30% (60.0 mm) for lateral side. For 140 mm stems, the percentage was 52.86% (74.0 mm) for medial side and 40.36% (56.5 mm) for lateral side. A neck length was shown to correlate significantly with the stem subsidence (P = 0.004). CONCLUSION: It is crucial to provide good contact between the bilateral cortical bone and stem, and, if possible, to select implant constructs with shorter femoral necks, in order to reduce subsidence and to ensure longer implant survivorship.

The neoacetabulum in developmental dysplasia of the hip is covered with hyaline cartilage.

The lack of adequate mechanical stimulation and appropriate contact between acetabulum and femoral head results with developmental dysplasia of the hip (DDH). In DDH, hip joint forms normally during the organogenesis, but deforms during the fetal development. Acetabulum remains comparable in width with normal acetabulum, but has increased length and decreased depth, resulting in a poor coverage of the femoral head. In cases of severe hip subluxation and luxation due to DDH, the femoral head articulates with the external side of the iliac bone, forming a neoacetabulum in the position that was genetically predetermined to become bony tissue. A neoacetabulum is therefore formed under intermittent mechanical pressure, but never has the depth of a physiological acetabulum due to different forces at this new location. Over time, the depth of the neoacetabulum increases, and a crest is formed that obstructs reposition of the femoral head into the anatomic acetabulum. We hypothesize that the neoacetabulum on the iliac bone in DDH patients is formed of hyaline cartilage, despite the lack of genetic predisposition for hyaline cartilage formation in this area. We assume that as the femoral head migrates during development in such patients, joint capsular tissue interposes between the external side of the iliac bone and the femoral head, and a cartilaginous metaplasia of the capsule follows. This results in elongation of the acetabular cartilage in the same direction as the femoral head migrated. This assumption is based on the finding that in patients with hip luxation such interposed joint capsule showed signs of cartilaginous transformation. Furthermore, in the inner part of such joint capsules, proteoglycan production was notably higher than that of other non-cartilaginous tissue. Also, high expression of cartilaginous genes, which are usually not expressed in this tissue, was observed. Confirmation of this hypothesis would put a new perspective on the pathogenesis of DDH and could lead to better management or even prevention of this condition.

Applications and critical evaluation of fascia iliaca compartment block and quadratus lumborum block for orthopedic procedures.

Anterior section of the hip joint capsule is innervated by femoral nerve and obturator nerve, and posterior section is innervated by the nerve to quadratus femoris muscle and occasionally by the superior gluteal (posterolateral region) and sciatic nerve (posterosuperior region). One of the regional anesthesia options for hip surgery is the fascia iliaca compartment block (FICB) that affects nerves important for hip innervation and sensory innervation of the thigh - femoral, obturator and lateral femoral cutaneous nerve. FICB can be easily performed and is often a good solution for management of hip fractures in emergency departments. Its use reduces morphine pre-operative requirement for patients with femoral neck fractures and can also be indicated for hip arthroplasty, hip arthroscopy and burn management of the region. Quadratus lumborum block (QLB) is a block of the posterior abdominal wall performed exclusively under ultrasound guidance, with still unclarified mechanism of action. When considering hip surgery and postoperative management, the anterior QLB has shown to reduce lengthy hospital stay and opioid use, it improves perioperative analgesia in patients undergoing hip and proximal femoral surgery compared to standard intravenous analgesia regimen, provides early and rapid pain relief and allows early ambulation, thus preventing deep vein thrombosis and thromboembolic complications etc. However, some nerve branches responsible for innervation of the hip joint are not affected by QLB, which has to be taken into consideration. QLB has shown potential for use in hip surgery and perioperative pain management, but still needs to be validated as a reliable treatment approach.

The plantaris muscle: too important to be forgotten. A review of evolution, anatomy, clinical implications and biomechanical properties.

Plantaris muscle (lat. musculus plantaris) is a fusiform muscle of the superficial posterior leg compartment, characterized with a small muscle belly and very long and slender tendon. Many anatomical variations of plantaris muscle have been reported previously, including its inconstancy. Evolutional studies strongly suggest that plantaris muscle is a rudimentary muscle that plays minor role in gait biomechanics. However, plantaris muscle seems to have very important proprioceptive role since it has very high density of muscle spindles. Clinically, plantaris muscle is involved in differential diagnosis of posterior leg pain and several pathological entities such as: plantaris muscle rupture, non-insertional Achilles tendinopathy and popliteal artery compression syndrome. Different surgical specialties have recognized plantaris muscle tendon as a valuable graft. However, literature on plantaris muscle tendon biomechanical properties is rather scant and inconsistent with several limitations for proper data comparison and interpretation. Further comparative studies are needed to properly define biomechanical properties of plantaris muscle tendon grafts for various ligament and tendon reconstructive procedures.

Femoral head wear and metallosis caused by damaged titanium porous coating after primary metal-on-polyethylene total hip arthroplasty: a case report.

Excessive metal femoral head wear has been described only as revision surgery complication after primary ceramic-on-ceramic total hip arthroplasty (THA). Here, we present the first case of metal femoral head wear after primary metal-on-polyethylene THA. A 56-year-old woman was referred to our outpatient clinic 17 years after primary right-sided THA, experiencing pain and decreased right hip range of motion. Radiographic examination revealed acetabular cup dislocation, eccentric femoral head wear, damaged titanium porous coating of femoral stem, metallosis, and pseudotumor formation. Endoprosthetic components were extracted, but further reconstruction was impossible due to presence of large acetabular bone defect. Macro- and micro-structure of extracted components were analyzed. Acetabular liner surface was damaged, with scratches, indentations, and embedded metal debris particles present on the entire inner surface. Analysis of metal debris by energy-dispersive spectroscopy showed that it consisted of titanium and stainless-steel particles. Femoral head was gravely worn and elliptically shaped, with abrasive wear visible under scanning electron microscope. No signs of trunnionosis at head/neck junction were observed. Microstructure of femoral head material was homogeneous austenitic, with microhardness of 145 HV 0.2, which is lower than previously described titanium hardness. In conclusion, detached titanium porous coating of femoral stem can cause stainless-steel femoral head wear in primary metal-on-polyethylene THA. As soon as such detachment becomes evident, revision surgery should be considered to prevent devastating complications.

Sport injuries in international masters rowers: a cross-sectional study.

AIM: To estimate the frequency and localization of acute (traumatic) and chronic (overuse) injuries in a population of masters rowers with respect to their age subgroups and assess the association between injury occurrence and different training modalities, rowing experience, previous competition level, and current rowing practice. METHODS: A cross-sectional study was conducted among 743 masters rowers who participated in the 34th International Federation of Rowing Associations (Fédération Internationale des Sociétés d'Aviron, FISA) World Rowing Masters Regatta held in Zagreb, September 2-9, 2007. A rowing-specific questionnaire was used, followed by an interview about the injuries sustained during the 12-month period before the competition. RESULTS: The mean injury rate per year was 0.48 injuries/masters rower (2.25 injuries/1000 training sessions/rower). The majority of injuries were chronic injuries (the ratio of acute to chronic injuries was 1:1.7), and did not lead to the loss of training/competition time. Of all acute injuries, 49.6% were acquired during rowing-specific training, 43.7% during cross-training, and 6.7% in the gym. The most commonly affected region was the low back (32.6%), followed by the knee (14.2%), shoulder/upper arm, and elbow (10.6% each). CONCLUSION: International masters rowers sustained predominantly chronic injuries of low severity, and the most commonly injured region was the low back. The mean injury rate per rower per year was lower than the rates previously reported for juniors and seniors.

Orthopedic and Cutaneous Reactions to Nickel after Total Hip Replacement.

Implant degradation products have shown signs of a cutaneous allergic response after implantation of a metal orthopedic replacement, loosening and failure of the joints as well as skin rashes, general fatigue, pain, and impaired wounds and bone healing. The prevalence of contact skin sensitivity in patients with a joint replacement device is higher than that in the general population. This delayed hypersensitivity to metallic orthopedic implants is more clearly defined and is a contributing factor to implant failure. Nickel was associated with hypersensitivity responses as the first cause in metallic orthopedic implants as early as 1966 by Foussereau and Laugieru and is a commonly used metal in alloys because it grants necessary strength and durability to the implant. Herein we report on delayed hypersensitivity to nickel sulfate in a patient with pain, fatigue, and contact allergic dermatitis in both inguinal regions, with instability of the left acetabular part and with five hip replacements from 1987 to 2013. The findings of this report support that primary sensitization to a metal due to an implant itself might develop. Proper investigation in patients with history or prior hypersensitivity reactions to metals and test evaluation before orthopedic device implantation is needed. before orthopedic device implantation is needed.

Mortality and causes of death among Croatian male Olympic medalists.

AIM: To compare the overall and disease-specific mortality of Croatian male athletes who won one or more Olympic medals representing Yugoslavia from 1948 to 1988 or Croatia from 1992 to 2016, and the general Croatian male population standardized by age and time period. METHODS: All 233 Croatian male Olympic medalists were included in the study. Information on life duration and cause of death for the Olympic medalists who died before January 1, 2017, was acquired from their families and acquaintances. We asked the families and acquaintances to present medical documentation for the deceased. Data about the overall and disease-specific mortality of the Croatian male population standardized by age and time period were obtained from the Croatian Bureau of Statistics (CBS). Overall and disease-specific standard mortality ratios (SMR) with 95% confidence intervals (CI) were calculated to compare the mortality rates of athletes and general population. RESULTS: Among 233 Olympic medalists, 57 died before the study endpoint. The main causes of death were cardiovascular diseases (33.3%), neoplasms (26.3%), and external causes (17.6%). The overall mortality of the Olympic medalists was significantly lower than that of general population (SMR 0.73, 95% CI 0.56-0.94, P=0.013). Regarding specific causes of death, athletes' mortality from cardiovascular diseases was significantly reduced (SMR 0.61, 95% CI 0.38-0.93, P=0.021). CONCLUSIONS: Croatian male Olympic medalists benefit from lower overall and cardiovascular mortality rates in comparison to the general Croatian male population.

Surgical Treatment of Moderate Hallux Valgus: A Comparison of Distal Chevron Metatarsal Osteotomy With and Without Lateral Soft-Tissue Release.

PURPOSE: The purpose of the study was to determine whether lateral soft-tissue release (LSTR) has a beneficial or detrimental effect on the outcome of distal Chevron first metatarsal osteotomy (DCMO) in the treatment of moderate hallux valgus (HV). METHODS: We compared the effect of different surgical treatments in 2 groups of patients: group I (23 patients, 25 feet, average age of 55 [from 43 to 77] years) was subjected to DCMO only, whereas group II (18 patients, 23 feet, average age of 59 [from 52 to 70] years]) was subjected to DCMO with LSTR. The American Orthopaedic Foot and Ankle Society's Hallux Metatarsophalangeal-Interphalangeal scale survey was conducted postoperatively, followed by the brief survey on postoperative patient satisfaction. The patient follow-up period was from 18 to 24 months after surgical treatment, on average. RESULTS: After surgical intervention, both groups of patients presented with an improved HV angle, but there was no significant difference between the groups. However, group II showed significant improvements in medial sesamoid bone position and patient satisfaction scores as compared with group I. CONCLUSION: Our midterm follow-up of surgical treatments for moderate HV deformity suggests that both procedures provide good postoperative results. However, according to our results, DCMO with LSTR provides better results than procedures without LSTR. LEVELS OF EVIDENCE: Therapeutic, Level III: Retrospective comparative study.

Hamate hook nonunion initially mistaken for ulnar nerve compression: a case report with review of literature.

BACKGROUND: Hamate hook (HH) stress fractures are rare, often presenting with misleading symptoms and easily overlooked/misdiagnosed. These fractures occur frequently in individuals participating in sports activities involving racquets, bats, or clubs. Symptoms are non-specific and often mimic other clinical conditions, such as ulnar nerve entrapment or ulnar vessel thrombosis. CASE REPORT: A 17-year-old tennis player with no history of trauma presented with dominant hand weakness together with pain and paresthesia on the ulnar side, which exacerbated with tennis play. The patient was treated for ulnar nerve compression with activity cessation and rest for 2 months. After 6 months of persistent symptoms, the patient underwent open Guyon tunnel release, although preoperative electromyoneurography revealed no signs of nerve damage and bone scans showed a small area of increased uptake in the hypothenar region. Postoperatively, symptoms resumed and the patient reported to our department for a second opinion. Point tenderness over HH, hypothenar muscles hypotrophy, paresthesia, hand weakness and pain with ulnar deviation, and flexion of distal phalanges of the two ulnar fingers were observed. HH fracture was suspected. Computerized tomography scan revealed fractured HH and the patient underwent hook excision. One month postoperatively, the pain intensity reduced together with function and strength improvement; 2 months postoperatively, the patient was pain free and had returned to tennis. CONCLUSIONS: In patients involved in racquet sports with hypothenar pain and paresthesia of the ulnar side of the hand, HH fracture should be suspected. Symptoms can mimic ulnar nerve entrapment and may lead to overlooking the correct diagnosis. Treatment of choice is fractured fragment excision.