Suture Anchor Versus Transosseous Tunnel Repair for Inferior Pole Patellar Fractures Treated With Partial Patellectomy and Tendon Advancement: A Biomechanical Study

Multifragment fracture of the patellar apex with extensive loss of skin: A case report

Introduction

Patella fractures account for 1 % of all skeletal fractures, and can interrupt the knee's extensor apparatus. They can also be serious if associated with a cutaneous opening. We report the case of a fracture of the tip of the patella with a large loss of cutaneous substance.

Case report

A 22-year-old man was admitted for the management of a left knee trauma following a motorcycle accident. Clinical examination revealed a large loss of skin substance on the anteromedial aspect of the knee, with exposed bone, pain and lack of extension of the left knee. Standard X-ray of the left knee showed an avulsion fracture of the tip of the patella. The patient underwent patellar tendon reconstruction using transosseous stitches, reinforced by a quadricipital tendon reversal plasty, and protected by steel-wire patellotibial cerclage. A medial gastrocnemius flap was used to cover the loss of skin substance. After a functional rehabilitation protocol, the functional results were satisfactory, with a full return to activity after six months.

Conclusion

The stability of osteosynthesis using quadricipital tendon reversal plasty and patellotibial cerclage allows mobilization and immediate weight-bearing. This may lead to better clinical results.

Study on the therapeutic effect of Kirschner wire tension band combined with anchor cross-stitch technique in the treatment of comminuted patellar inferopolar fractures

PURPOSES

Fractures of the inferior patellar pole, unlike other patellar fractures, present challenges for traditional surgical fixation methods. This article introduces the clinical technique and outcomes of using Kirschner wire tension band combined with anchor screw cross-stitch fixation for comminuted inferior patellar pole fractures.

METHODS

This retrospective case series study included 14 patients with comminuted inferior patellar pole fractures treated at our institution from September 1, 2020, to April 30, 2022. All patients underwent surgery using the Kirschner wire tension band with anchor screw cross-stitch technique. Follow-up assessments involved postoperative X-rays to evaluate fracture healing, as well as clinical parameters such as healing time, Visual Analog Scale (VAS) scores, range of motion (ROM), and Bostman scores.

RESULTS

All patients were followed for an average of over 12 months, with no cases of internal fixation failure. Knee joint stability and function were excellent. X-rays revealed an average healing time of approximately 10.79 ± 1.53 weeks, hospitalization lasted 5.64 ± 1.15 days, surgery took approximately 37.86 ± 5.32 minutes, and intraoperative blood loss was 33.29 ± 8.15 ml. One patient experienced irritation from the internal fixation material. At the final follow-up, the Bostman score averaged 28.29 ± 0.83, knee joint flexion reached 131.07° ± 4.88°, all patients achieved full knee extension, and the VAS score was 0.36 ± 0.63.

CONCLUSION

Kirschner wire tension band with anchor screw cross-stitch fixation for comminuted inferior patellar pole fractures delivered satisfactory clinical outcomes. This surgical method, characterized by its simplicity and reliability, is a valuable addition to clinical practice.

Computational evaluation of wire position using separate vertical wire technique and candy box technique for the fixation of inferior pole patellar fractures: a finite element analysis

The separate vertical wire (SVW) technique and the improved candy box (CB) technique have been proposed for treating inferior pole patellar fractures. However, there is still a lack of clear explanation regarding the location of the wire passing through the patella. Five models of SVW techniques were established in different positions. Finite element analysis was then conducted to determine the optimal bone tunnel position for the SVW technique. Based on these findings, six groups of finite element models were created for CB techniques. The maximum displacement and stress on both the patella and steel wire were compared among these groups under 100-N, 200-N, 300-N, 400-N, and 500-N force loads. The results indicated that, in the SVW technique, the steel wire group near the fracture end of the longitudinal bone tunnel showed minimal displacement and stress on the patella when subjected to different forces. On the other hand, in the CB technique, both the patella and wire experienced minimal stress when a transverse bone tunnel wire was placed near the upper posterior aspect of patella. In conclusion, the SVW technique may require the bone tunnel wire to be positioned near the fractured end of the lower pole of the patella. On the other hand, in CB technique, the transverse bone tunnel wire passing through the patella may be close to its upper posterior aspect. However, further validation is necessary through comprehensive finite element analysis and additional biomechanical experiments.

Suture Anchor Repair for Distal Patellar Tendon Avulsion in Tibial Tubercle Fractures: A Technical Description and Report of Two Cases

Tibial tubercle avulsion fractures, though rare, pose a significant challenge in pediatric orthopedics, particularly in athletic adolescents. For nondisplaced fractures, conservative treatment involves the use of braces or casts, while displaced fractures necessitate operative intervention, often through screw fixation. Concomitant soft tissue injuries should also be identified and addressed operatively to ensure complete repair of the extensor mechanism. This paper introduces a method for open reduction and internal fixation (ORIF) of tibial tubercle fractures with suture anchor repair of the distal patellar tendon avulsion. Two case examples of 14-year-old males with displaced fractures undergoing this procedure are presented. After standard screw fixation of the displaced fragment was performed, a single suture anchor was placed into the tibia and an onlay tension slide technique was utilized to secure the distal patellar tendon avulsion. Both patients underwent immobilization and protected weightbearing for four weeks with physical therapy initiated at six weeks. At four months postoperatively, both patients had returned to competitive sports without issue. The described technique may represent a reliable and reproducible method for addressing the distal patellar tendon avulsion component of tibial tubercle fractures. Its biomechanical advantages contribute to the complete repair of the extensor mechanism, enabling a successful return to competitive athletics without hardware complications.

Suture Anchor Fixation Has Less Gap Formation and No Difference in Complications or Revisions for Patellar Tendon Repair: A Systematic Review

PURPOSE

To evaluate the literature on suture anchor (SA) usage for patellar tendon repair, summarize the overall biomechanical and clinical outcomes, and assess whether the cumulative research supports the adoption of this technique compared with transosseous (TO) repair.

METHODS

A systematic literature review using the Preferred Reporting Items for Systematic and Meta-Analyses guidelines was performed. Multiple electronic databases were searched to identify studies focusing on surgical outcomes of patellar tendon repair with suture anchor usage. Cadaver and animal biomechanical studies, technical studies, and clinical studies were included.

RESULTS

A total of 29 studies met the inclusion criteria: 6 cadaver, 3 animal, 9 technical, and 11 clinical reports. Four of the 6 cadaver studies and 1 of the 2 animal studies found significantly less gap formation from SA than from TO repair. Average gap formation in human studies ranged from 0.9 to 4.1 mm in the SA group compared with 2.9 to 10.3 mm in TO groups. Load to failure was significantly stronger in 1 of 5 cadaver studies and 2 of 3 animal studies, with human studies SA load to failure ranging from 258 to 868 N and TO load to failure ranging from 287 to 763 N. There were 11 clinical studies that included 133 knees repaired using SA. Nine studies showed no difference between complication rate or risk for reoperation, where one study reported a significantly lower re-rupture rate after SA repair compared with TO repair.

CONCLUSIONS

SA repair is a viable option for patellar tendon repair and could have several advantages over TO repair. Multiple studies indicate that SA repair has less gap formation during biomechanical testing compared with TO repair in human cadaver and animal models. No differences in complications or revisions were found in the majority of clinical studies.

CLINICAL RELEVANCE

Both animal and human models suggest SA fixation has potential biomechanical benefits when compared with TO tunnels for patellar tendon repair, whereas clinical studies show no difference in complications and revisions postoperatively.

A novel technique of a new cannulated screw for treatment of inferior pole patellar fractures: a finite element study

OBJECTIVE

We invented a new cannulated screw with holes on the tail, which called Ding's screw. The goal of this study was to evaluate the biomechanical outcomes of this new screw with tension band wiring for the treatment of inferior pole patellar fractures in a finite element model.

METHODS

We conducted a finite element biomechanical study using two fixation methods: Ding's screw and tension band wiring (DSTBW) and cannulated screws and tension band wiring (CSTBW). Two methods were simulated to fix the inferior pole patellar fracture in a finite element model. The relative displacement and stress distribution were analyzed and compared.

RESULT

There were less displacement and stress distribution of DSTBW in different knee movement (30°, 60°, 90°, 120°) when compared to CSTBW. The highest value of displacement of the fracture and von Mises stress of the internal fixation happened in 120° knee movement in both groups. The highest displacement of the DSTBW was less than that of the CSTBW (1.92 mm to 2.12 mm). The highest value of the stress on the screws was 110.60 MPa in DSTBW group, and 132.90 MPa in CSTBW group. The highest value of the stress on the titanium cable was 38.51 MPa in DSTBW group, and 41.91 MPa in CSTBW group.

CONCLUSION

DSTBW fixation provides more stability than CSTBW fixation model in a finite element study.

Separate vertical wiring plus bilateral anchor girdle suturing fixation for the fractures of the inferior pole of the patella

BACKGROUND

The fixation of inferior pole fractures of the patella (IPFPs) is still a great challenge for surgeons.

MATERIALS AND METHODS

We introduced a new fixation method for IPFP fixation, that is, separate vertical wiring plus bilateral anchor girdle suturing fixation (SVW-BSAG). Three finite element models including the anterior tension band wiring (ATBW) model, separate vertical wiring (SVW) model and SVW-BSAG model, were built to evaluate the fixation strength of different fixation methods. A total of 41 consecutive patients with IPFP injury were enrolled in this retrospective study, including 23 patients in the ATBW group and 18 patients in the SVW-BSAG group. The operation time, radiation exposure, full weight-bearing time, Bostman score, extension lag versus contralateral healthy leg, Insall-Salvati ratio, and radiograph outcomes were employed to assess and compare the ATBW group and SVW-BSAG group.

RESULTS

The finite element analysis confirmed that the SVW-BSAG fixation method was as reliable as the ATBW fixation method in terms of fixed strength. Through retrospective analysis, we found that there was no significant difference between the SVW-BSAG and ATBW groups in age, sex, BMI, fracture side, fracture type, or follow-up time. There were no significant differences between the two groups in the Insall-Salvati ratio, 6-month Bostman score, and fixation failure. Compared with the ATBW group, the SVW-BSAG group showed advantages in intraoperative radiation exposure, full weight-bearing time, and extension lag versus the contralateral healthy leg.

CONCLUSION

The finite element analysis and clinical results showed that SVW-BSAG fixation methods are a reliable and valuable for IPFP treatment.

Transosseous suture versus suture anchor fixation for inferior pole fractures of the patella in osteoporotic bone: a biomechanical study

BACKGROUND

The surgical treatment of inferior patellar pole fractures can be a challenge, especially in geriatric patients, who are particularly frequently affected by osteoporosis. The objective of this biomechanical study was to compare the performance of suture anchor and transosseous suture fixation in fractures of the inferior patellar pole in context of bone mineral density.

METHODS

Twelve fresh-frozen human cadaveric knees received a transverse osteotomy, simulating an AO/OTA 34C1.3 inferior pole fracture of the patella. These fractures were fixated with either suture anchors (SA; Corkscrew^® FT 4.5 mm) or transosseous suture (TS; #2 FiberWire^®). Cyclic loading tests were performed by pulling the quadriceps tendon against gravity from 90° flexion to almost full extension (5°) for 1000 cycles. Motion and fracture gap displacement were tracked until failure occurred. Subsequently, loading to failure tests followed. Differences between groups were compared using unpaired t-tests, and correlations were calculated with Pearson's correlation coefficient.

RESULTS

The suture anchor group showed significantly fewer cycles to failure than the transosseous suture group (SA: 539.0 ± 465.6 cycles, TS: 1000 ± 0 cycles, P = 0.04). Bone mineral density correlated positively with cycles to failure in the suture anchor group (Pearson's r = 0.60, P = 0.02). No differences in fracture gap displacement could be proven after 100 cycles (SA: 4.1 ± 2.6 mm, TS: 6.5 ± 2.6 mm, P = 0.19); 500 cycles (SA: 6.4 ± 6.1 mm, TS: 9.6 ± 3.8 mm, P = 0.39); and 1000 cycles (SA: 4.0 ± 0.4 mm, TS: 11.0 ± 4.5 mm, P = 0.08). Furthermore, the mean destructive load to failure in the suture anchor group was also significantly lower than in the transosseous suture group (SA: 422.4 ± 212.2 N, TS: 825.7 ± 189.3 N, P = 0.04).

CONCLUSIONS

Suture anchors may be a viable alternative to transosseous suture in younger patients for clinical advantages, but in osteoporotic bone, the more stable osteosynthesis with transosseous suture continues to prove superior. Therefore, trauma surgeons might consider the use of transosseous suture in elderly patients, especially in those presenting with low bone mineral density values.

Design and Validation of a Smile-Necklace Plate for Treating Inferior Patellar Pole Avulsion Fractures: A Review and Hypothesis

The patella's inferior pole transmits force generated by contraction of the quadriceps muscle to the tibial tuberosity through the attached patellar ligament, thus completing knee extension. Therefore, fractures of the patella's inferior pole disrupt the coherence of mechanical transmission in the lower extremities. There appears to be no consensus among trauma centers regarding the treatment of infrapatellar pole fractures, primarily because there is no consistent design or application of internal fixation for this type of fracture. We designed a new internal implant similar to the smile necklace based on our previous study. This smile‐necklace plate (SNP) has the advantage of both plate fixation and tension‐band wiring fixation, permitting early rehabilitation, especially in osteoporotic comminuted infrapatellar pole fractures. Finite element analysis helped verify the biomechanical advantages of the SNP in comparison with existing studies. Hence, this novel implant is a promising treatment option for inferior pole patellar fractures.

Failure Rates of Suture Anchor Fixation Versus Transosseous Tunnel Technique for Patellar Tendon Repair: A Systematic Review and Meta-analysis of Biomechanical Studies

Background

Transosseous tunnel (TO) repair is considered the gold standard for patellar tendon rupture; however, suture anchor (SA) repair has emerged as a viable alternative in recent years. Although both these techniques are used widely in clinical practice, the most biomechanically optimal construct for patellar tendon repair remains unknown.

Purpose

To examine published studies on the biomechanical properties of TO and SA fixation for patellar tendon repair in terms of ultimate load to failure and cyclic gap formation. The null hypothesis was that there would be no significant difference in either outcome measure between the groups.

Study Design

Systematic review.

Methods

A systematic review using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed by searching PubMed, the Cochrane Library, and Embase to identify studies that analyzed the biomechanical properties of SA and TO techniques for repair of a ruptured patellar tendon. The search phrase implemented was "patellar tendon repair." Meta-analysis was performed to provide a quantitative comparison of the 2 techniques with regard to ultimate load to failure and cyclic gap displacement. Weighted averages were calculated for all quantitative outcomes, and outcomes were summarized in a forest plot. A random-effects model was used to account for the heterogeneity among the included studies in the final statistical analysis.

Results

Of 875 studies initially screened, the inclusion criteria were met by 7 studies, including 128 cadaveric specimens (66 SA, 62 TO). The pooled analysis from 6 studies reporting on gap displacement revealed a statistically significant difference in favor of SA versus TO fixation (P < .001). Pooled analysis from 7 studies reporting on ultimate load to failure did not reveal a statistically significant difference between the use of SA and TO for tendon repair (P = .465).

Conclusion

Our systematic review revealed that the use of SA fixation for patellar tendon repair was associated with lower cyclic gap displacement when compared with TO fixation. There was no significant difference in ultimate load to failure between the repair techniques.