Autologous chondrocyte implantation for the treatment of osteochondral lesions of the talus: What happens after 20 years?

BACKGROUND: The purpose of this study was to assess the long-term clinical efficacy of first-generation autologous chondrocyte implantation (ACI) technique for osteochondral lesions of the ankle joint. METHODS: Eleven patients with symptomatic OLTs underwent ACI from December 1997 to October 2002. A total of 9 patients (5 men, 4 women, age 25.2 ± 6.3) were evaluated at baseline and at 1, 3, 10 years, and at final follow-up of minimum 20 years with AOFAS ankle-hindfoot score, NRS for pain, and with the Tegner score. RESULTS: The AOFAS score improved significantly from the baseline value of 40.4 ± 19.8 to 82.7 ± 12.9 at the final follow-up (p < 0.0005). The NRS for pain improved significantly from 7.8 ± 0.7 at baseline to 4.8 ± 2.1 at the final follow-up (p < 0.0005). Moreover, the Tegner score underwent a modification from the pre-operative median value of 1 (range: 1-3) and from a pre-injury value of 5 (range: 3-7) to 3 (range: 2-4) at the final follow-up (p < 0.0005). CONCLUSIONS: ACI has proven to be an effective treatment option for patients suffering from OLTs, leading to a long-lasting clinical improvement even beyond 20 years of follow-up. LEVEL OF EVIDENCE: Level IV.

Indications, Associated Procedures, and Results of Ankle Plafond-Plasty for Varus Ankle Osteoarthritis: A Systematic Review and Meta-Analysis.

BACKGROUNDS: Plafond-plasty is a joint-preserving procedure to treat varus ankle osteoarthritis (OA) with asymmetrical joint involvement. The aim of this systematic review and meta-analysis was to evaluate indications, different surgical techniques, associated procedures, and results of plafond-plasty in varus ankle OA and to analyze the level of evidence (LOE) and quality of evidence (QOE) of the included studies. METHODS: A systematic review of the literature was performed using MEDLINE, Embase, and Cochrane. RESULTS: Five studies evaluating 99 ankles were included. A non-rigid varus ankle deformity and an ankle OA Takakura stage 3b or less were the most recommended pre-operative indications. Meta-analysis showed a significant post-operative improvement in clinical and radiological parameters. Many associated surgical procedures have been reported, the most frequent being medial additional supramalleolar osteotomy and lateral ankle ligament reconstruction. The level of evidence and methodological quality assessment of the included studies showed an overall low quality. CONCLUSION: Plafond-plasty seems to be a promising surgical option when managing varus ankle OA with asymmetrical joint involvement, extending the indications for joint sparing surgery. Additional associated procedures should be carefully evaluated case-by-case. LEVELS OF EVIDENCE: IV.

Restoration of Spinopelvic Alignment After Reduction of High-grade Spondylolisthesis: Myth or Reality? A Systematic Review of the literature and Meta-analysis.

STUDY DESIGN: Systematic review and meta-analysis of literature. OBJECTIVE: The aim of the presented study is to assess whether the reduction of high-grade spondylolisthesis (HGS) through the correction of lumbosacral kyphosis leads to a decrease in the sagittal spinopelvic compensatory mechanisms. SUMMARY OF BACKGROUND DATA: HGS is as an anterior translation of a vertebra, >50%. It is also characterized by a kyphotic deformity of the affected level. This combination of translation and kyphosis leads to compensatory mechanisms on the sagittal plane [pelvic retroversion, increased lumbar lordosis (LL), reduction in thoracic kyphosis (TK)]. METHODS: A systematic search of electronic databases was conducted. Inclusion criteria were diagnosis of HGS (Meyerding >II, Slip% >50%), partial or complete reduction surgery (with a significant decrease in Slip%), and report of spinopelvic parameters (pelvic incidence, pelvic tilt, or sacral slope). Clinical and radiographic outcomes were extracted and summarized. Meta-analyses were performed to estimate the differences between preoperative and postoperative spinopelvic alignment measures. P<0.05 was considered significant. RESULTS: Eighteen studies were included. PT showed a statistically significant decrease of -2.1217 (95% CI: -3.4803 to -0.7630), while SS showed a significant increase of 4.8349 (95% CI: 2.7462-6.9236). Conversely, both LL and TK showed nonsignificant changes, -4.7043 (95% CI: -10.4535 to 1.0449) and 6.3881 (95% CI: -0.8344 to 13.6106), respectively. VAS significantly decreased by -3.1950 (95% CI: -4.9462 to -1.4439). CONCLUSIONS: The meta-analysis showed mild, yet statistically significant, decrease of PT and an increase in SS after HGS reduction. Conversely, nonstatically significant decrease in LL and an increase in TK occurred. The clinical significance of these results remains questionable. LEVEL OF EVIDENCE: Level IV.

Comparable rates of lumbar disc degeneration at long-term following adolescent idiopathic scoliosis spinal fusion extended to L3 or L4: systematic review and meta-analysis.

PURPOSE: Surgical treatment of adolescent idiopathic scoliosis (AIS) requires a careful choice of fusion levels. The usual recommendation for the selection of the lowest instrumented vertebra (LIV) for double major or thoracolumbar/lumbar (TL/L) curves falls on L3 or L4. The aim of the present study is to assess if the spinal fusion with LIV selection of L3 or L4 in AIS patients has a clinical or radiological impact in terms of degenerative disc disease (DDD) in distal unfused segments at long-term follow-up. METHODS: A systematic search of electronic databases from eligible articles was conducted. Only studies regarding long-term follow-up of AIS patients treated with spinal fusion were included. Clinical and radiographic outcomes were extracted and summarized. Meta-analysis on long-term follow-up MRI studies was performed. p value < 0.05 was considered significant. RESULTS: Fourteen studies were included, for a total of 1264 patients. Clinical assessment of included patients showed a slight tendency to have worse clinical outcomes if spinal fusion is extended to L4 rather than L3. Despite that, meta-analysis could not be performed on clinical parameters because of heterogeneity of evaluated PROMs in included studies. Magnetic resonance imaging (MRI) evaluation at long-term follow-up showed no significant difference in terms of disc degeneration rate at overall meta-analysis (p = 0.916) between patients fused to L3 and L4. CONCLUSION: The LIV selection of L3 rather than L4, according to current literature, does not prevent disc degeneration in distal unfused segments over the long term. Long-term studies of patients treated with contemporary spinal instrumentation are needed.

Hallux Valgus Plantar Pressure Distribution before and after a Distal Metatarsal Osteotomy.

Background: Hallux valgus (HV) morphological alterations impact forefoot kinetics. Surgery aims to restore both the morphology and function. Plantar pressure (PP) distribution systems represent an innovative additional tool to evaluate the hallux functional outcome after surgery in order to assess the hallux dorsiflexion, coupled with plantar flexion of the first ray. However, the literature reports limited evidence regarding the rebalancing of the plantar pressure distribution following surgery. The purpose of the present study was to examine the PP distribution in HV patients before and after a distal metatarsal osteotomy using a novel anatomically based protocol for in-shoe plantar load analysis during gait. Methods: A consecutive series of 18 patients with mild-to-moderate symptomatic HV who underwent a distal metatarsal osteotomy (S.E.R.I. technique) were prospectively evaluated using clinical scores (AOFAS and NRS), radiographic parameters (hallux valgus angle, intermetatarsal angle), and PP measurements via W-INSHOE© (Medicapteurs, Balma, France). Data were collected preoperatively and 12 months after surgery. Results: At 12 months follow-up, 3 patients were lost to follow-up, leaving 15 patients (24 HV) for examination. Both clinical and radiographical outcomes showed significant improvements from the pre- to postoperative periods. The PP distribution pattern revealed a significant increase in the peak pressure under the first metatarsal head associated with a significant increase in the peak pressure under the central metatarsals area between the pre- and postoperative periods. Conclusions: PP measurement systems hold promise as an additional clinical tool, yet current findings remain inconclusive. Further long-term follow-up studies that incorporate additional parameters are warranted.

Hip-spine relationship: clinical evidence and biomechanical issues.

The hip-spine relationship is a critical consideration in total hip arthroplasty (THA) procedures. While THA is generally successful in patient, complications such as instability and dislocation can arise. These issues are significantly influenced by the alignment of implant components and the overall balance of the spine and pelvis, known as spinopelvic balance. Patients with alteration of those parameters, in particular rigid spines, often due to fusion surgery, face a higher risk of THA complications, with an emphasis on complications in instability, impingement and dislocation. For these reasons, over the years, computer modelling and simulation techniques have been developed to support clinicians in the different steps of surgery. The aim of the current review is to present current knowledge on hip-spine relationship to serve as a common platform of discussion among clinicians and engineers. The offered overview aims to update the reader on the main critical aspects of the issue, from both a theoretical and practical perspective, and to be a valuable introductory tool for those approaching this problem for the first time.

Unveiling dysplasia epiphysealis hemimelica (Trevor's disease) in the foot and ankle: A systematic review.

Background: Dysplasia epiphysealis hemimelica is a rare non-inherited condition characterized by the unilateral predominance of osteochondromas in one or more epiphyses, with ankles and knees being the most affected joints. Treatment approaches vary based on the localization of the disease, encompassing both conservative and surgical options. Due to its rarity, there is a lack of definitive surgical guidelines or specific treatment modalities. Therefore, the objective of this systematic review was to thoroughly investigate dysplasia epiphysealis hemimelica to provide evidence-based guidance for managing this condition, specifically focusing on the foot and ankle. Methods: A systematic search was performed on PubMed and the Cochrane Library to identify all published articles related to dysplasia epiphysealis hemimelica of the foot and ankle. Individual patient information, such as gender, age, disease type, follow-up, localization, clinical presentation, intervention, and complications, were systematically extracted from each article and analyzed. Results: Twenty-five eligible publications were included in the review, involving a total of 70 patients (16 females, 53 males). The mean age was 9.6 years (SD 7.3). The talus was the most prevalent location and clinical presentations included mass and pain in 54% of cases. Surgical procedures were chosen in 92% of patients, with 95% undergoing mass excision. Recurrence was the most frequent complication, observed in 9% of cases. Conclusions: Raising awareness about dysplasia epiphysealis hemimelica is crucial for early diagnosis and treatment, positively impacting clinical outcomes. Vigilant monitoring is essential during observational management, as unchecked mass growth can complicate surgical intervention. Surgical treatment focuses on mass excision, feasible even at a young age but requiring precision to prevent recurrence or secondary arthritis. Level of evidence: IV.

Are there gender-specific differences in hip and knee cartilage composition and degeneration? A systematic literature review.

The aim of the present review is to systematically analyse the current literature about gender differences in hip or knee cartilage composition and degeneration, to help explaining how and why osteoarthritis affects women more often and more severely than men. A systematic review of the literature in English was performed. Eleven studies on 1962 patients (905 females and 787 males) that reported differences on cartilage composition between males and females were included. Nine evaluated the knee, one the hip, and one both. They were heterogeneous in their methods: one conducted histological analyses, and all the others evaluated cartilage characteristics (volume, width, and composition) through magnetic resonance imaging. All authors reported gender differences in both volume and morphology of the cartilage, from infancy to menopause. In fact, a study on 92 healthy children statistically showed significant gender differences in cartilage thickness at all sites, even after adjustment for age, body, and bone size. Gender differences become more evident after menopause, when women have a lower cartilage volume and a higher cartilage loss. Men show significantly higher knee and hip cartilage volumes than women, and women carry a significantly greater risk to develop osteoarthritis. This is in part due to body and bone size, but also depends on qualitative and quantitative differences in the composition of cartilage and its degeneration rate after menopause. Structural changes in cartilage that occur between genders during ageing have significance in the development of osteoarthritis.

Collagen VI Deficiency Impairs Tendon Fibroblasts Mechanoresponse in Ullrich Congenital Muscular Dystrophy.

The pericellular matrix (PCM) is a specialized extracellular matrix that surrounds cells. Interactions with the PCM enable the cells to sense and respond to mechanical signals, triggering a proper adaptive response. Collagen VI is a component of muscle and tendon PCM. Mutations in collagen VI genes cause a distinctive group of inherited skeletal muscle diseases, and Ullrich congenital muscular dystrophy (UCMD) is the most severe form. In addition to muscle weakness, UCMD patients show structural and functional changes of the tendon PCM. In this study, we investigated whether PCM alterations due to collagen VI mutations affect the response of tendon fibroblasts to mechanical stimulation. By taking advantage of human tendon cultures obtained from unaffected donors and from UCMD patients, we analyzed the morphological and functional properties of cellular mechanosensors. We found that the length of the primary cilia of UCMD cells was longer than that of controls. Unlike controls, in UCMD cells, both cilia prevalence and length were not recovered after mechanical stimulation. Accordingly, under the same experimental conditions, the activation of the Hedgehog signaling pathway, which is related to cilia activity, was impaired in UCMD cells. Finally, UCMD tendon cells exposed to mechanical stimuli showed altered focal adhesions, as well as impaired activation of Akt, ERK1/2, p38MAPK, and mechanoresponsive genes downstream of YAP. By exploring the response to mechanical stimulation, for the first time, our findings uncover novel unreported mechanistic aspects of the physiopathology of UCMD-derived tendon fibroblasts and point at a role for collagen VI in the modulation of mechanotransduction in tendons.

The Medium- to Long-Term Results of Vascular-Sparing Subcapital Osteotomy (VASSCO) for Pediatric Patients with Chronic Slipped Capital Femoral Epiphysis.

Background: In patients affected by chronic slipped capital femoral epiphysis (C-SCFE), the performance of a subcapital osteotomy is an effective procedure to correct the deformity at the proximal femur. However, the rate of postoperative complications is very high, with iatrogenic avascular necrosis of the femoral head (AVN) being the most bothersome. To overcome the risk of AVN, the modified Dunn procedure according to Ganz and, more recently, the Vascular Sparing Subcapital Osteotomy (VASSCO) technique have been proposed; however, only short-term follow-up studies are available on the latter technique being used. The aim of this study is therefore to show our mid-term clinical and radiological results with the VASSCO technique. Materials and Methods: A total of 26 patients underwent VASSCO for moderate or severe stable C-SCFE between 2012 and April 2016 with an average 10-year follow-up (range 8-12 years). The outcomes was evaluated using the HHS and pre- and postoperative ROM. The radiological outcomes and complications were collected. Results: No major intraoperative complications occurred; three patients reported postoperative transient apraxia of the lateral femoral cutaneous nerve, which completely recovered in six months. All the radiological outcomes showed substantial improvement postoperatively. One case patient developed AVN of the femoral head and required a total hip arthroplasty after 12 years. Conclusions: The current data suggest that VASSCO osteotomy is a reliable technique with very good clinical results at mid-term follow-up; it could be considered a valuable alternative to using more complex techniques to restore the proximal femoral anatomy in moderate to severe C-SCFE.

Frailty Influence on Postoperative Surgical Site Infections After Surgery for Degenerative Spine Disease and Adult Spine Deformity. Can a Frailty Index be a Valuable Summary Risk Indicator? A Systematic Review and Metanalysis of the Current Literature.

STUDY DESIGN: Metanalysis. OBJECTIVE: Surgical site infections (SSI) is one of the commonest postoperative adverse events after spine surgery. Frailty has been described as a valuable summary risk indicator for SSI in spine surgery. The aim of this metanalysis is to evaluate the influence of frailty on postoperative SSI in this cohort and provide hints on which index can predict the risk of SSI. METHODS: Papers describing the postoperative SSI rate in adult degenerative spine disease or adult spine deformity patients with varying degrees of frailty were included in the analysis. The SSI rate in different grades of frailty was considered for outcome measure. Meta-analysis was performed on studies in whom data regarding patients with different levels of frailty and occurrence of postoperative SSI could be pooled. P < .05 was considered significant. RESULTS: 16 studies were included. The frailty prevalence measured using mFI-11 ranged from 3% to 17.9%, these values were inferior to those measured with mFI-5. Significant difference was found between frail and non-frail patients in postoperative SSI rate at metanalysis (z = 5.9547, P < .0001 for mFI-5 and z = 3.8334, P = .0001 for mFI-11). CONCLUSION: This is the first meta-analysis to specifically investigate the impact of frailty, on occurrence of SSI. We found a relevant statistical difference between frail and non-frail patients in SSI occurrence rate. This is a relevant finding, as the ageing of population increases alongside with spine surgery procedures, a better understanding of risk factors may advance our ability to treat patients while minimizing the occurrence of SSI.

Pedicle Dysplasia in Proximal Thoracic Adolescent Idiopathic Scoliosis Curves: What are We Missing and What are its Possible Surgical Implications? An Observational Retrospective Study on 104 Patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To assess if pedicle dysplasia is present in proximal thoracic (PT), both structural and nonstructural, compared to main thoracic (MT) curves; and to assess if it is predictive of radiographic outcomes at minimum 2 years of follow-up. METHODS: A retrospective review of surgically-treated Adolescent Idiopathic Scoliosis (AIS) patients with Lenke 1-2-3-4 curves was performed. On preoperative CT-scan, at the apical vertebra, pedicle width on the concavity (PWc) and on the convexity (PWv) and Pedicle Dysplasia Index (PDI, defined as PWc/PWv) were measured. Preoperative and last follow-up (at least 2 years) x-rays were reviewed. RESULTS: 104 patients meeting the inclusion criteria were divided into Structural-PT (S-PT) and Nonstructural-PT (NS-PT) groups based on Lenke criteria. PWc (P < .001). And PDI (P < .001 for S-PT, P = .004 for NS-PT) were significantly smaller in the PT than in MT curves for both groups. PT-PWc significantly correlated with follow-up PT Cobb for both groups (P < .001 and P = .015 respectively). PT-PDI significantly correlated with follow-up PT-Cobb (P < .001), CA (P < .040) and T1 tilt (P < .002), only for NS-PT group. NS-PT patients with PWc PT <1 mm had higher RSHD (P = .021) and T1 tilt (P = .025) at follow-up. NS-PT patients with PDI PT <.3 had higher RSHD (P < .001), CA (P = .002) and T1 tilt (P = .003) at follow-up. CONCLUSION: S-PT and NS-PT curves show significant pedicle dysplasia on the concavity. Pedicle dysplasia significantly correlated with shoulder balance at follow-up, for NS-PT patterns. Patients with a PWc <1 mm or PDI <.30 are at particular risk of postoperative shoulder imbalance.

Arthroscopic surgery for scaphoid nonunion: a 10-year systematic literature review.

The purpose of the study was to investigate whether arthroscopic treatment of carpal scaphoid nonunions by osteosynthesis with bone grafting represents a successful surgical technique. This systematic literature review, conducted following the PRISMA guidelines, explores the past 10 years of clinical studies concerning the arthroscopic treatment of scaphoid nonunions. The most relevant keywords were used to search the databases, and the Downs and Black 27-item checklist has been used as quality assessment tool. Twelve papers that meet the premised eligibility criteria have been identified. These studies demonstrate the efficacy of this surgical solution, achieving a postoperative union rate of 96% in the average time of 13.5 weeks. Regardless of the method of synthesis and the origin of the graft used, excellent results were obtained. Patients who underwent this procedure reported a pain reduction of almost 80% compared to the preoperative level, improvement in grip strength close to 40%, and recovery in wrist function during daily activities. Arthroscopy has numerous advantages compared to the open approach. These are technically recognized by the surgeon and by the patient. Some disadvantages include a longer intraoperative time and considerable significant technical difficulty. Arthroscopic treatment of scaphoid nonunion by osteosynthesis with bone graft achieves a 96% union rate of the treated scaphoid with satisfying clinical results.

Sex does not influence the long-term outcome of matrix-assisted autologous chondrocyte transplantation.

PURPOSE: Regenerative techniques for articular cartilage lesions demonstrated heterogeneous clinical results. Several factors may influence the outcome, with sex being one of the most debated. This study aimed at quantifying the long-term influence of sex on the clinical outcome obtained with a regenerative procedure for knee chondral lesions. METHODS: Matrix-assisted autologous chondrocyte transplantation (MACT) was used to treat 235 knees which were prospectively evaluated with the International Knee Documentation Committee (IKDC), EuroQol visual analogue scale, and Tegner scores at 14-year mean follow-up. A multilevel analysis was performed with the IKDC subjective scores standardised according to the age/sex category of each patient and/or the selection of a match-paired subgroup to compare homogeneous men and women patients. RESULTS: At 14 years, men and women showed a failure rate of 10.7% and 28.8%, respectively (p < 0.0005). An overall improvement was observed in both sexes. Women had more patellar lesions and men more condylar lesions (p = 0.001), and the latter also presented a higher preinjury activity level (p < 0.0005). Men had significantly higher IKDC subjective scores at all follow-ups (at 14 years: 77.2 ± 18.9 vs. 62.8 ± 23.1; p < 0.0005). However, the analysis of homogeneous match-paired populations of men and women, with standardised IKDC subjective scores, showed no differences between men and women (at 14 years: -1.6 ± 1.7 vs. -1.9 ± 1.6). CONCLUSION: Men and women treated with MACT for knee chondral lesions presented a significant improvement and stable long-term results. When both sexes are compared with homogeneous match-paired groups, they have similar results over time. However, women present more often unfavourable lesion patterns, which proved more challenging in terms of long-term outcome after MACT. LEVEL OF EVIDENCE: Level II.

Investigating the Differential Circulating microRNA Expression in Adolescent Females with Severe Idiopathic Scoliosis: A Proof-of-Concept Observational Clinical Study.

Adolescent Idiopathic Scoliosis (AIS) is the most common form of three-dimensional spinal disorder in adolescents between the ages of 10 and 18 years of age, most commonly diagnosed in young women when severe disease occurs. Patients with AIS are characterized by abnormal skeletal growth and reduced bone mineral density. The etiology of AIS is thought to be multifactorial, involving both environmental and genetic factors, but to date, it is still unknown. Therefore, it is crucial to further investigate the molecular pathogenesis of AIS and to identify biomarkers useful for predicting curve progression. In this perspective, the relative abundance of a panel of microRNAs (miRNAs) was analyzed in the plasma of 20 AIS patients and 10 healthy controls (HC). The data revealed a significant group of circulating miRNAs dysregulated in AIS patients compared to HC. Further bioinformatic analyses evidenced a more restricted expression of some miRNAs exclusively in severe AIS females. These include some members of the miR-30 family, which are considered promising regulators for treating bone diseases. We demonstrated circulating extracellular vesicles (EVs) from severe AIS females contained miR-30 family members and decreased the osteogenic differentiation of mesenchymal stem cells. Proteomic analysis of EVs highlighted the expression of proteins associated with orthopedic disease. This study provides preliminary evidence of a miRNAs signature potentially associated with severe female AIS and suggests the corresponding vesicular component may affect cellular mechanisms crucial in AIS, opening the scenario for in-depth studies on prognostic differences related to gender and grade.

Ponte Osteotomies in the Surgical Treatment of Adolescent Idiopathic Scoliosis: A Systematic Review of the Literature and Meta-Analysis of Comparative Studies.

The purpose of the present paper is to assess if Ponte osteotomies (POs) allow for a better correction in adolescent idiopathic scoliosis (AIS) surgery and to investigate their safety profile. A systematic search of electronic databases was conducted. Inclusion criteria: comparative studies that reported the outcomes of AIS patients who underwent surgical correction through posterior-only approach with and without POs. Clinical and radiographic outcomes were extracted and summarized. Meta-analyses were performed to estimate the differences between patients treated with and without POs. p < 0.05 was considered significant. In total, 9 studies were included. No significant difference in thoracic kyphosis (TK) change between patients treated with and without POs was found (+3.8°; p = 0.06). Considering only hypokyphotic patients, a significant difference in TK change resulted in POs patients (+6.6°; p < 0.01), while a non-significant TK change resulted in normokyphotic patients (+0.2°; p = 0.96). No significant difference in coronal correction (2.5°; p = 0.10) was recorded. Significant estimated blood loss (EBL) (142.5 mL; p = 0.04) and surgical time (21.5 min; p = 0.04) differences were found with POs. Regarding complications rate, the meta-analysis showed a non-significant log odds ratio of 1.1 (p = 0.08) with POs. In conclusion, POs allow for the restoration of TK in hypokyphotic AIS, without a significantly greater TK change in normokyphotic patients, nor a significantly better coronal correction. Considering the significantly greater EBL and the trend toward a higher complications rate, the correct indication for POs is crucial.

Cementless Primary Stems in Revision Hip Arthroplasty: A Narrative Review.

Cementless primary stems in revision hip arthroplasties may be conservative options to preserve bone stock and provide adequate reconstruction of the hip biomechanics. However, there is still little evidence about indications, limitations, and outcomes. This narrative review showed that conventional standard stems were adopted in different revision settings, up to Paprosky IIIA grade bone defects. In cases of acceptable metaphyseal bone stock, when a scratch fit of at least 4 cm can be achieved, a conventional cementless stem may be an adequate solution. Mid-term clinical and radiographic outcomes and survival rates were similar to long revision stems, whereas complications, surgical time, and costs were lower among conventional stems. However, unsuitable contexts for conventional stems included canal diameters larger than 18 mm and failed revision stems with cortical weakening. Even short stems can be considered in revisions, in order to preserve bone stock and stay proximal to femoral remodeling zones and bone/cement plugs. Short stems were successfully adopted up to Paprosky IIIA bone defects, achieving mid-term survival rates not inferior to long revision stems. Ageing, osteoporosis, and intraoperative femoral fractures were the main negative prognostic factors. In very select cases, a downsizing technique (from longer to shorter stems) may be adopted to simplify the procedure and reduce complications.

Direct Anterior Approach in Total Hip Arthroplasty for Severe Crowe IV Dysplasia: Retrospective Clinical and Radiological Study.

Background and Objectives: total hip arthroplasty (THA) for Crowe IV hip dysplasia poses challenges due to severe leg shortening, muscle retraction and bone stock issues, leading to an increased neurological complication, and revision rate. The direct anterior approach (DAA) is used for minimally invasive THA but its role in Crowe IV dysplasia is unclear. This retrospective study examines if DAA effectively restores hip biomechanics in Crowe IV dysplasia patients with <4 cm leg length discrepancy, managing soft tissue and yielding functional improvement, limb length correction, and limited complications. Materials and Methods: 19 patients with unilateral Crowe IV hip osteoarthritis and <4 cm leg length discrepancy undergoing DAA THA were reviewed. Surgery involved gradual soft tissue release, precise acetabular cup positioning, and stem placement without femoral osteotomy. Results: results were evaluated clinically and radiographically, with complications recorded. Follow-up revealed significant Harris Hip Score and limb length discrepancy improvements. Abductor muscle insufficiency was present in 21%. The acetabular component was accurately placed, centralizing the prosthetic joint's rotation. Complications occurred in 16% of cases, including fractures, nerve issues, and infection. DAA in THA showcased positive outcomes for hip function, limb length, and biomechanics in Crowe IV dysplasia. Conclusions: the technique enabled accurate cup positioning and rotation center adjustment. Complications were managed well without implant revisions. DAA is a viable option for Crowe IV dysplasia, restoring hip function, biomechanics, and reducing limb length discrepancy. Larger, longer studies are needed for validation.