Young-Soo Shin

Location of the femoral tunnel aperture in single-bundle anterior cruciate ligament reconstruction: comparison of the transtibial, anteromedial portal, and outside-in techniques.

Background: Previous 3-dimensional computed tomography (3D CT) studies of knees after anterior cruciate ligament (ACL) reconstruction have compared femoral tunnel positions obtained using the transtibial and anteromedial drilling techniques. This study used postoperative in vivo 3D CT analysis to compare the locations of the femoral tunnel aperture among 3 drilling techniques used in ACL reconstruction: transtibial, anteromedial portal, and outside-in. Hypothesis: The use of the transtibial drilling technique might result in a less anatomically accurate femoral tunnel placement than the anteromedial portal and outside-in techniques. Study Design: Cohort study; Level of evidence, 3. Methods: Immediate postoperative in vivo 3D CT was used to assess the location of the femoral tunnel aperture in 153 patients who underwent single-bundle ACL reconstruction using the transtibial (n = 42), anteromedial portal (n = 73), or outside-in (n = 38) techniques. Femoral tunnel positions were measured by an anatomic coordinate axis method in the low-to-high and deep-to-shallow directions of the distal femur at 90° of knee flexion. Results: The low-to-high femoral tunnel positions were significantly higher in the transtibial group than in the anteromedial portal (P < .001) and outside-in (P < .001) groups. There were no differences among the 3 groups in the deep-to-shallow femoral tunnel positions (P = .773). Conclusion: The transtibial technique of anatomic reconstruction resulted in more highly positioned femoral tunnels in the low-to-high direction than did the anteromedial portal and outside-in techniques. However, no significant differences in the femoral tunnel location were observed in the deep-to-shallow direction.

Comparison of kinematic and mechanical alignment techniques in primary total knee arthroplasty: A meta-analysis

Background: This meta-analysis compared clinical and radiographic outcomes and complications of kinematic alignment (KA) and mechanical alignment (MA) techniques in primary total knee arthroplasty (TKA). Methods: All studies comparing the operation time, change in hemoglobin, length of hospital stay, postoperative complications, and clinical and radiographic outcomes as assessed with various measurement tools, from direct interview to imaging methods, in patients who underwent primary TKA through the KA or MA technique were included. Results: Six studies were included in the meta-analysis. The proportion of patients who developed postoperative complications (OR: 1.10, 95% CI: 0.49–2.46; P = .69) did not differ significantly between the KA and MA techniques. The 2 groups were also similar in terms of change in hemoglobin (95% CI: −0.38 to 0.34; P = .91), length of hospital stay (95% CI: −0.04 to 0.55; P = .10), hip-knee-ankle angle (95% CI: −1.76 to 0.75; P = .43), joint line orientation angle (95% CI: −4.27 to 4.23; P = .99), tibial component slope (95% CI: −0.53 to 3.56; P = .15), and femoral component flexion (95% CI: −2.61 to 7.57; P = .34). In contrast, operation time (95% CI: −27.16 to −3.71; P = .01), overall functional outcome (95% CI: 6.59–11.51; P < .0001), knee anatomical axis (95% CI: −1.38 to −0.01; P = .05), femoral component relative to the mechanical axis (95% CI: −2.47 to −1.40; P < .0001), and tibial component relative to the mechanical axis (95% CI: 1.56–2.95; P < .0001) were significantly different between the 2 groups. Conclusions: There were no significant differences in postoperative complications, change in hemoglobin, length of hospital stay, hip-knee-ankle angle, joint line orientation angle, tibial component slope, or femoral component flexion between the KA and MA techniques for primary TKA. However, the KA technique resulted in a significantly shorter operation time and better overall functional outcome than the MA technique, even though the femoral component was placed in a slightly more valgus position relative to the mechanical axis and the tibial component in a slightly more varus position with the KA technique.

Prospective randomized study comparing two cephalomedullary nails for elderly intertrochanteric fractures: Zimmer natural nail versus proximal femoral nail antirotation II

OBJECTIVES Although both clinical and biomechanical studies suggest that cephalomedullary implants have a mechanical advantage over extramedullary implants, a high rate of complications or implant failure remains in elderly patients with osteoporosis. In an attempt to address some of these challenges, new implants with improved designs named proximal femoral nail antirotation II (PFNA II) and Zimmer natural nail (ZNN) were developed for elderly patients. Although the PFNA II reportedly has good clinical outcomes, it is unclear which implant achieves better safety and efficacy for treating intertrochanteric hip fractures. The primary objective of this prospective, randomized trial involved 353 patients was to evaluate Harris Hip Score (HHS). The secondary objective was to compare results associated with clinical outcome such as operation time, fluoroscopy time, lateral hip pain, walking ability, and reoperation rate as well as the incidence of cut-out by using implant position and fracture reduction quality. METHODS 353 patients with an intertrochanteric fracture amenable to either ZNN implant or PFNA II with a mean age of 77.0 years and a mean follow-up period of 12.3 months were included. We analyzed 353 patients with an intertrochanteric fracture treated using a ZNN implant (n=172, group I) or a PFNA II (n=181, group II) between January 2011 and August 2014. RESULTS There were no significant inter-group differences in HHS, walking ability, and reoperation rate were observed. However, operation and fluoroscopy time were significantly different between the two groups as well as group I showed a higher incidence of lateral hip pain than group II. In addition, no significant inter-group differences in cut-out rate determined by implant position and fracture reduction quality. We also found that cut-out was associated with lag screw position in the femoral head measured by Tip-apex distance (TAD) but not with reduction quality. CONCLUSIONS Although group I had significant longer operation and fluoroscopy time than group II, both implants are useful tools in the treatment of elderly intertrochanteric fractures as well as only TAD, but not Cleveland zone significantly correlated with lag screw cut-out.

Comparison of Dorsal and Volar Percutaneous Approaches in Acute Scaphoid Fractures: A Meta-Analysis

The dorsal approach allows better central screw placement along the long axis of the scaphoid compared with the volar approach in managing acute scaphoid fractures. However, it is unclear whether the dorsal approach leads to better clinical outcomes than the volar approach. This meta-analysis compared clinical outcomes, including the incidence of nonunion, postoperative complications, overall functional outcome, postoperative pain, grip strength, and range of wrist motion, between the dorsal and volar percutaneous approaches for the management of acute scaphoid fractures. Seven studies met the criteria for inclusion in the meta-analysis. The proportion of patients who developed nonunion (OR 0.74, 95% CI: 0.21 to 2.54; P = 0.63) and postoperative complications (OR 1.05, 95% CI: 0.45 to 2.44; P = 0.91) did not differ significantly between the dorsal and volar approaches. Both approaches also led to similar results in terms of overall functional outcome (95% CI: -0.39 to 0.22; P = 0.57), postoperative pain (95% CI: -0.52 to 0.46; P = 0.92), grip strength (95% CI: -4.56 to 1.02; P = 0.21), flexion (95% CI: -2.86 to 1.13; P = 0.40), extension (95% CI: -1.17 to 2.67; P = 0.44), and radial deviation (95% CI: -1.94 to 2.58; P = 0.78). However, ulnar deviation (95% CI: -7.48 to 0.05; P = 0.05) was significantly greater with the volar approach. Thus, orthopedic surgeons need to master both the dorsal and volar percutaneous approaches because not all acute scaphoid fractures can be dealt with completely with one approach.

Popliteal artery pseudoaneurysm following primary total knee arthroplasty.

An early diagnosis of popliteal artery pseudoaneurysm-a sequela of popliteal artery trauma-is difficult owing to its late presentation following total knee arthroplasty. The incidence of a popliteal artery pseudoaneurysm with a hematoma presenting only a peripheral nerve injury after total knee arthroplasty is also uncommon in the absence of common diagnostic features such as a pulsatile swelling with an audible bruit on auscultation. In the present report, we describe popliteal artery pseudoaneurysm following total knee arthroplasty.

Comparison of Specific Femoral Short Stems and Conventional-Length Stems in Primary Cementless Total Hip Arthroplasty.

There are several reported disadvantages with conventional-length femoral stems in cementless total hip arthroplasty (THA). Therefore, various efforts have been made to develop a specific femoral short stem to improve physiologic bone remodeling at the femoral aspect of a cementless THA. However, there are potential disadvantages with specific femoral short stems, such as malalignment, inadvertent subsidence, and potential proximal femoral fracture. Therefore, the authors quantitatively compared radiographic and clinical outcomes as well as component-specific complications between 2 groups of patients following primary cementless THA. A matched comparison was made between specific femoral short stems (n=50) and conventional-length femoral stems (n=50) in cementless THA procedures performed between January 2008 and January 2012. Patients were matched for age, sex, body mass index, height, surgical approach, and surgeon. No significant differences were found between the 2 groups in mean postoperative radiographic outcomes, functional outcomes, or complications. Both groups showed satisfactory performance at 5-year follow-up. Specific femoral short stems resulted in a higher incidence of malalignment and subsidence and a lower incidence of thigh pain and proximal bone resorption compared with conventional-length femoral stems. Although longer follow-up is required, specific femoral short stems may have clinical and radiographic advantages with equivalent perioperative complications relative to conventional-length femoral stems. However, this technique requires proper patient selection in combination with careful preoperative planning and meticulous surgical technique.

No Clinically Important Difference in Knee Scores or Instability Between Transtibial and Inlay Techniques for PCL Reconstruction: A Systematic Review

BackgroundIt is unclear whether the biomechanical superiority of the inlay technique over the transtibial technique, arising from avoidance of the killer turn at the graft-tunnel margin of the proximal tibia during posterior cruciate ligament (PCL) reconstruction, leads to better knee scores or greater knee stability.Questions/purposesThis systematic review was designed to compare Tegner and Lysholm scores, and posterior residual laxity of the knee, between single-bundle PCL reconstruction using transtibial and inlay techniques.MethodsWe searched MEDLINE®, Embase®, and the Cochrane Library for studies comparing Tegner and/or Lysholm scores and posterior residual laxity, in patients who underwent PCL single-bundle reconstruction with the transtibial and tibial inlay techniques. There were no restrictions on language or year of publication. Studies were included if they compared clinical outcomes in patients who underwent PCL single-bundle reconstruction with the transtibial and tibial inlay techniques; they simultaneously reported direct comparisons of transtibial and tibial inlay PCL single-bundle reconstruction; and their primary outcomes included comparisons of postoperative scores on knee outcome scales and posterior residual laxity. A total of seven studies (including 149 patients having surgery using a transtibial approach, and 148 with the tibial inlay approach) met the prespecified inclusion criteria and were analyzed in detail.ResultsOur systematic review suggested that there are no clinically important differences between the transtibial and the tibial inlay single-bundle PCL reconstruction in terms of Tegner or Lysholm scores. Of the five studies that assessed Lysholm scores, one favored the transtibial approach and four concluded no difference on this endpoint; however, the observed differences in all studies where differences were observed were quite small (< 7 of 100 points on the Lysholm scale), and likely not clinically important. Of the four studies that compared postoperative Tegner scores, three identified no differences between the approaches, while one favored the tibial inlay approach by a small margin (0.5 of 11 points) suggesting that there likely is no clinically important difference between the approaches in Tegner scores, either. Finally, we identified no difference between the approaches in terms of residual laxity, either among the seven studies that presented data using Telos radiographs, or the five that reported on patients with residual laxity greater than Grade 2 on a four-grade scale of posterior drawer testing (28/107 for transtibial and 26/97 for tibial inlay).ConclusionWe found no clinically important differences between the transtibial and tibial inlay approach for PCL reconstruction. Based on the best evidence now available, it appears that surgeons may select between these approaches based on clinical experience and the specific elements of each patient’s presentation, since there do not appear to be important or obvious differences between the approaches with respect to knee scores or joint stability. Future randomized trials are needed to answer this question more definitively.Level of EvidenceLevel III, therapeutic study.

Mid-term outcomes of floating platform mobile-bearing total knee arthroplasty under navigational guidance with a minimum 4-year follow-up.

We evaluated 106 knees that underwent primary total knee arthroplasty (TKA) with the navigation-assisted gap balancing technique using an e.-motion cruciate retaining floating platform (FP) mobile-bearing prosthesis to prospectively assess the survival of the e.-motion FP system after a minimum follow-up of 4 years. There was no evidence of any complications, including dissociation or breakage of the polyethylene liner or component loosening at last follow up (5.1 ± 0.6 years). Four knees, however, required re-operation, three for distal femoral fracture, and one for infection. The estimated 5-year prosthesis survival rates without revision for any reason and for prosthesis-associated problems were 96.2% and 100%, respectively. The e.-motion floating platform, with a cruciate retaining design under navigation guidance, demonstrated excellent clinical results and 5-year survival rate.

Vaginal mass following uncemented total hip arthroplasty

A 53-year-old woman developed a vaginal mass following an uncemented total hip arthroplasty. The mass was in direct communication with the hip through an acetabular medial wall defect after loosening of the acetabular component. The mass formation was caused simultaneously by changes secondary to polyethylene wear, a tiny delamination of the porous titanium mesh coating and a broken antirotational tab on the acetabular cup, all of which may have served as sources of metal particles. A careful evaluation of the patients history, symptoms, X-ray findings and computed tomography scans should always be performed to ensure accurate diagnosis.

Better clinical outcomes after unicompartmental knee arthroplasty when comparing with high tibial osteotomy

Background: Both high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are well-established treatments for medial knee osteoarthritis (OA). However, it is unclear whether HTO or UKA leads to better clinical outcomes and lower complication rates. This meta-analysis compared the clinical outcomes and complications of HTO and UKA in patients with medial knee OA. Methods: All studies comparing the functional outcome, postoperative pain, revision rate to total knee arthroplasty (TKA), postoperative complications, postoperative velocity, and postoperative range of motion (ROM) as assessed with various measurement tools in patients with medial knee OA treated with HTO or UKA were included. Results: Sixteen studies were included in the meta-analysis. The proportion of patients who underwent revision to TKA (OR 1.56, 95% CI: 0.61–3.98; P = .35) did not differ significantly between HTO and UKA. In contrast, functional outcome (OR 0.47, 95% CI: 0.24 to 0.95; P = .04), postoperative pain (OR 0.28, 95% CI: 0.12 to 0.62; P = .002), postoperative complications (OR 2.48, 95% CI: 1.26 to 4.90; P = .009), postoperative velocity (95% CI: −0.11 to −0.00; P = .03), and postoperative ROM (95% CI: 2.02 to 15.23; P = .01) were significantly different between the 2 groups. Conclusions: There were no significant differences in the revision rate to TKA between HTO and UKA. However, results from subgroup analyses suggested that opening-wedge HTO resulted in a lower revision rate to TKA than did UKA, whereas closing-wedge HTO resulted in a higher revision rate to TKA than did UKA. In addition, UKA resulted in significantly better functional outcomes and postoperative velocity, along with less postoperative pain, fewer postoperative complications, and lower postoperative ROM. Based on the findings of current meta-analysis, UKA appears to be as efficacious and safe as HTO in the treatment of medial knee OA.