Paul Pei-Hsi Chou

Humeral capitellum osteochondritis dissecans (OCD) is a common condition among overhead throwing athletes and is typically treated surgically. While stable lesions can be treated nonoperatively, untreated unstable lesions can lead to significant elbow discomfort and impaired quality of life. This study reviews the revision rate and interval in athletes with elbow OCD following primary surgery. Data was extracted from PubMed, Embase, and Medline between 1990 and 2022, and two reviewers independently screened the duplicate reports of complications and revision surgeries. The Methodological Index for Nonrandomized Research score was used for risk of bias assessment. Inclusion criteria were as follows: studies in the English language, those involving humans, those reporting complications, and those performing revision surgeries following capitellar OCD surgery. Logit transformation and random effects were calculated using the Der Simonian Laired estimator, and the Shapiro–Wilk test was first performed to determine whether revision interval data followed a normal distribution. The Wilcoxon rank sum test was used for nonparametric data comparison, while Spearman’s rank correlation assessed whether shorter follow-up periods underestimated the revision rate. A total of 6,457 studies were identified through the initial literature search (PubMed: 1,924; Embase: 2,532; Medline: 2,001), with 4,147 duplicates removed, leaving 2,310 unique studies for screening. After applying the inclusion criteria, 20 full-text articles were selected, all of which were level IV case series with MINORS scores ranging from 7 to 14 (mean: 10.65), demonstrating moderate heterogeneity (I2 = 41%) and strong inter-reviewer agreement across screening phases (κ = 0.78–0.98). Twenty studies involving 477 elbows (474 athletes) were included, 55 of which underwent revision surgery. The athletes were divided into debridement, microfracture, and osteochondral grafting groups. The overall revision rate was 11.53%, and the revision rate of the three groups were 11.2%, 14.2%, and 9.19%, respectively. Eleven of the 20 studies (24 of 175 athletes underwent revision surgery) with complete data were included in interval analysis of revision surgery. The mean intervals of all participants and three groups were 25, 41.8, 10.4, and 24.2 months, respectively. Spearman’s rank correlation showed no significant association between the follow-up duration and the revision rate (rho = –0.31, p = 0.18) or the revision interval (rho = 0.02, p = 0.95) in the overall cohort. Correlation coefficients across surgical subgroups also varied in direction and were not statistically significant. Approximately 11% of patients required revision surgery following primary treatment for elbow OCD, with an average interval of 25 months. No significant association between follow-up duration and either revision rate or revision interval. Thus, further investigations, rehabilitation programs may be required to decrease this revision rate.

Background/Objectives: This novel compression screw design offers potential benefits due to its two-part structure and can be used for various bone types, much like a conventional single-piece compression screw. However, full engagement may not always occur after final compression in clinical practice. This study aimed to verify the hypothesized optimal mechanical strength when the two parts are nearly fully combined and to determine a recommended engagement range based on stress distribution and concentration using finite element analysis. Methods: Ten models representing different combinations of the two screw parts (ranging from 10% to 100% of the engagement length, at 10% intervals) were simulated to determine the acceptable engagement percentage. Pull-out and bending load simulations were performed using finite element models. Extreme clinical loading conditions were simulated, including 1000 N pull-out forces and a 1 Nm bending moment at the screw head. Results: Finite element analysis revealed two stress concentration points. The pull-out load simulation showed that combinations with 100% engagement merged the two stress concentrations into one without force superposition, while combinations with less than 30% engagement should be avoided. In the bending load simulation, higher stress was observed for combinations with less than 90% engagement. A lower level of engagement increases the bending moment, which might be the major factor affecting the von Mises stress. Conclusions: Surgeons should be instructed on how to use the screw correctly and select the most appropriate screw size or length for the two parts to achieve an effective combination. Excessive bending or pull-out forces, or improper use with poor combinations, may cause the middle interval to strip or the screw to break or pull out. An engagement of more than 90% is recommended, while less than 30% is considered dangerous. This study provides biomechanical insights into this novel two-part screw design and its important clinical implications.

Background/Objectives: The pullout failure of conventional locking screws (LSs, screws with a locking mechanism) may occur in patients with osteoporosis, particularly when inserted near joints or across periarticular fractures (e.g., proximal humerus). The two-part locking cancellous screw modification (TP-LCS, screws composed of two parts) in metaphyseal cancellous bone is hypothesized to increase bone purchase and holding power. This study aimed to test the hypothesized advantages of TP-LCS over LSs. Methods: An MTS 370 series frame with an axial/torsional load cell was used to test driving torque and axial pullout strength, following ASTM F543-07 standards. The TP-LCS group featured a newly modified screw design made from titanium alloy (Ti6Al4V), while conventional LSs (Synthes) were used for the control group. Statistical significance was assessed for selected comparisons relevant to the research objectives, including driving torque and axial pullout strength. Results: The driving torque test showed that TP-LCS had a significantly higher maximum insertion torque (4.9 ± 0.4 N·cm) compared to LSs (4.2 ± 0.4 N·cm) (p = 0.0269), although no significant difference was found in maximum removal torque (p = 0.1046). The axial pullout test revealed that TP-LCS had significantly higher pullout strength (223.5 ± 12.2 N) compared to LSs (203.5 ± 11.5 N) (p = 0.0284). Failure during the axial pullout test often involved cracking of the test block material around the screw threads, causing the screw to pull out. Conclusions: These results support the hypothesis that TP-LCS may offer improved axial pullout resistance compared to LSs, making it a potentially beneficial modification for LSs in osteoporotic metaphyseal regions or near joints. This study provides biomechanical insights into the advantages of the modified screw design over conventional LSs.

Background: The comparison between the mini-midvastus (mini-MV) and mini-parapatellar (mini-MPP) approach in total knee arthroplasty (TKA) remains a subject of debate. The present study compared quadriceps activation, pain levels, and clinical outcomes between the two approaches; quadricep activation was assessed using surface electromyography (sEMG). Methods: This retrospective cross-sectional study comprised a total of 78 patients aged between 50 and 85 years with primary osteoarthritis. Patients were divided into a mini-MV (n = 38) group and a mini-MPP (n = 40) group according to the surgical approach. Results: The two groups exhibited no significant differences in sEMG for the vastus medialis (VM) or rectus femoris (RF) at the follow-up time points, with the exception that the mini-MV group exhibited superior strength of RF during extensions at the 2-week follow-up. However, the mini-MPP group had superior Western Ontario and McMaster Universities Index (WOMAC) total and function scores at the 2- and 6-week follow-ups. The mini-MPP group also had superior WOMAC stiffness scores at the 2-week follow-up. The two groups did not differ significantly in terms of pain levels or morphine consumption. Conclusions: The sEMG data of quadriceps muscle would not differ significantly between the mini-MV and mini-MPP approaches for TKA. Moreover, the mini-MPP approach may yield superior WOMAC scores when compared with the mini-MV approach.

Article Superior-medial pole of the bipartate patella was published on June 8, 2023 in the journal Journal of Osteopathic Medicine (volume 0, issue 0).

Background and Objectives: For the treatment of knee osteoarthritis (OA), intra-articular platelet-rich plasma (PRP) and novel crosslinked single-dose hyaluronic acid (HA) have both been reported to improve outcomes, but no study has compared them for the treatment of knee OA. We hypothesized patients with early-stage knee OA who received PRP injections would have more WOMAC score changes than those who received HA injections. This is the first prospective, double-blind, parallel, randomized controlled trial comparing the efficacy of intra-articular single-dose PRP versus novel crosslinked HA (HyajointPlus) for treating early-stage knee OA. Materials and Methods: This study analyzed 110 patients randomized into the PRP (n = 54) or HA (n = 56) groups. The primary outcome is the change of WOMAC score at 1-, 3-, and 6-month follow-ups compared to baseline. Results: The data revealed significant improvements in all WOMAC scores in the PRP group at 1-, 3-, and 6-month follow-up visits compared with the baseline level except for the WOMAC stiffness score at the 1-month follow up. In the HA group, significant improvements were observed only in the WOMAC pain score for all the follow-up visits and in WOMAC stiffness, function, and total scores at 6-month follow-up. When comparing the change of WOMAC score at 1-, 3-, and 6-month follow-ups, no significant differences were found between PRP and HA group. Conclusions: This study revealed that both PRP and HA can yield significant improvements in WOMAC scores at 6-month follow-up without any between-group differences at 1-, 3-, and 6-month follow-ups. Thus, both the single-injection regimens of PRP and HA can improve the functional outcomes for treating early-stage knee OA.

This study aimed to systematically review the literature on the impact of the coronavirus disease (COVID-19) pandemic on the orthopedics field by focusing on multiple aspects, including orthopedic training and application, performance, work loading, change of practice, research work, and other psychological factors. Published articles were searched using the PubMed database. Articles were selected in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of 58 studies published between 1 January 2020 and 1 October 2021, 57 peer-reviewed original articles were included. Nearly 90% of students experienced an impact of the pandemic on application. The impact on training stemmed from redeployment rates of 20.9–23.1%. The rate of emergency or outpatient visits decreased from 18% to 58.6%. The rates of all surgeries or emergency surgeries decreased by 15.6–49.4%, while the rates of elective surgeries decreased by 43.5–100%. The rate of work loading ranged from 33% to 66%. Approximately 50–100% of surgeons had a change of practice. A total of 40.5% of orthopedic surgeons experienced mild psychological pressure. Approximately 64% had stopped research participant recruitment. Most of the included studies were conducted in Europe, followed by Asia and North America. It is suggested orthopedic surgeons prepare more sufficient, flexible, and reservable staffing measures, proper preventive strategies and surgical scheduling algorithms, and set up dedicated venues and equipment for routine telemedicine with staff training for virtual teaching or consultations in case of future impacts on orthopedics.

Ligament reconstruction is indicated in patients with an isolated posterior cruciate ligament (PCL) injury who fail conservative treatment. To eliminate the need for PCL reconstruction, an ideal rehabilitation program is important for patients with an isolated PCL injury. The purpose of this study was to investigate the improvement in functional outcome, proprioception, and muscle strength after a Both Sides Up (BOSU) ball was used in a balance combined with strength training program in patients with an isolated PCL injury. Ten patients with isolated PCL injuries were recruited to receive a 12 week training program as a study group. In the control group (post-PCL reconstruction group), ten subjects who had undergone isolated PCL reconstruction for more than 2 years were enrolled without current rehabilitation. The Lysholm score, IKDC score, proprioception (active and passive), and isokinetic muscle strength tests at 60°/s, 120°/s, and 240°/s, were used before and after training on the injured and normal knees in the study group, and in the post-PCL reconstruction group. The results were analyzed with a paired t-test to compare the change between pre-training, post-training, and the normal leg in the study group, and with an independent t-test for comparisons between the study and post-PCL reconstruction groups. Both the Lysholm and IKDC scores were significantly improved (p < 0.01) after training, and no difference was observed compared to the post-PCL reconstruction group. The active and passive proprioception was improved post-training compared to pre-training, with no difference to that in the post-PCL reconstruction group. Isokinetic knee quadriceps muscle strength was significantly greater post-training than pre-training in PCL injured knees at 60°/s, 120°/s, and 240°/s, and in hamstring muscle strength at 60°/s and 120°/s. Muscle strength in the post-training injured knee group showed no significant difference compared to that in the post-training normal leg and the post-PCL reconstruction group. The post-training improvement of muscle strength was higher in the PCL injured leg compared to the normal leg and there was no difference between the dominant and non-dominant injured leg in the study group. After 12 weeks of BOSU balance with strength training in patients with an isolated PCL injury, the functional outcome, proprioception, and isokinetic muscle strength were significantly improved, and comparable to the contralateral normal leg and the post-PCL reconstruction group. We suggest that programs combining BOSU balance and strength training should be introduced in patients with a PCL injury to promote positive clinical results.

The purpose of this study was to build on existing qualitative to quantitative approaches to develop a new quantitative method for evaluating pelvic and trunk rotational pitching mechanics. Thirty pitchers were divided into two groups (“Pattern1”: closed “hip-to-shoulder separation”; “Pattern2”: open “hip-to-shoulder separation”). Several parameters were analyzed. Higher ball speeds were found in group of Pattern1, four key characteristics of which were identified. Based on the results, a new evaluation method was developed. Pelvic and trunk rotational mechanics were classified into four types. Type1 (proper mechanics) enabled significantly higher ball speed than the other three types and was thought to involve proper energy transfer from the stride foot to the throwing upper limb. Types 2–4, however, were regarded as “improper mechanics”, which could result in slower ball speeds and less efficient energy transfer. A qualitative approach, based on “expert opinion”, can specify optimal pelvis and trunk rotational mechanics. However, quantitative analysis is more precise in identifying three improper types of pelvis and trunk rotational mechanics. Furthermore, special programs, such as core strengthening and flexibility training, can be developed for various improper practices in order to improve pitching mechanics.