Subtalar Fusion Preparation: What Are We Really Doing? A Cadaver Study

Operative Time, Cost, and Union Rate of Power Rasp Joint Preparation Versus Traditional Preparation in Arthrodesis of the Foot and Rearfoot

Time spent in the operating room is valuable to both surgeons and patients. One of the biggest rate-limiting factors when it comes to arthrodesis procedures of the foot and ankle is cartilage removal and joint preparation. Power instrumentation in joint preparation provides an avenue to decrease joint preparation time, thus decreasing operating room time and costs. Arthrodesis of 47 joints (n) from 27 patients were included. Power rasp joint preparation in 26 joints was compared to traditional osteotome and curette joint preparation in 21 joints in both time (seconds), cost (total operating room time cost per minute), and union rate. The overall mean joint preparation time using power rasp for the subtalar joint was 268.3 seconds, talonavicular joint 212.3 seconds, calcaneocuboid joint 142.6 seconds, 1st TMT 107.2 seconds. Mean joint preparation time using traditional method for subtalar joint 509.8 seconds, talonavicular joint 393.0 seconds, calcaneocuboid joint 400.0 seconds, 1st TMT 319.6 seconds. Mean cost of joint preparation using power rasp for subtalar joint $165.47, talonavicular joint $130.89, calcaneocuboid joint $87.94, 1st TMT $66.11. Mean cost of joint preparation using traditional techniques for subtalar joint $314.34, talonavicular joint $242.35, calcaneocuboid joint $246.67, 1st TMT $197.33. Overall union rate was 98% (1 asymptomatic non-union). Increasing efficiency in the operating room is vital to every surgeon's practice. Power rasp joint preparation is a viable option to increase efficiency and decrease operative time, this study shows no statistically significant differences in union rate, with comparable rates to existing literature.

Open vs Minimally Invasive Resection of the First Metatarsocuneiform Joint: An Anatomical Study

BACKGROUND

The modified Lapidus arthrodesis is a standard procedure to correct middle to severe hallux valgus (HV) deformities. Recently, minimally invasive techniques of first metatarsocuneiform joint (MCJ) resection using a Shannon burr were described. The primary goal of this study is to compare the anatomical efficacy and safety of first MCJ resection using a straight 2 × 13-mm Shannon burr and minimally invasive technique (MIS) vs an open technique using an oscillating saw.

METHODS

Ten pairs of fresh frozen cadaveric feet were randomly assigned to open or MIS first MCJ resection with subsequent systematic dissection. For the MIS procedure, a dorsomedial approach was used and for the open procedure a medioplantar approach was used. Cartilage removal was investigated by analyzing standardized scaled photographs of the resected articular surfaces with ImageJ software. Nearby structures at risk were analyzed for iatrogenic violation: tibialis anterior (TA), extensor hallucis longus (EHL) and peroneus longus (PL) tendons, and the Lisfranc ligament complex (LLC).

RESULTS

In the MIS group, the median cartilage resection was 85.9% at the cuneiform and 85.6% at the metatarsal bone compared to 100% cartilage resection in open technique (P < .01). Iatrogenic damage of the LLC, EHL, and TA tendons was not found in any group. The PL tendon was thinned out (<25% of tendon thickness) in 4 cases (40%) in the open group and in 1 case (10%) in the MIS group. A safe zone of 3.0 mm between the articular surface of the cuneiform bone and the LLC was identified, which can be resected without putting the LLC at risk when performing lateral-based wedge resections.

CONCLUSION

In this cadaver study with the procedures performed by an experienced foot and ankle surgeon, and using 2 different surgical approaches, we found general parity between the Shannon burr MIS technique vs oscillating saw open technique techniques with more risk to the PL with our open technique and approximately 15% less cartilage resection with our MIS technique.

LEVEL OF EVIDENCE

Level V, cadaver study.

Quality of MIS vs Open Joint Preparations of the Foot and Ankle

BACKGROUND

Minimally invasive surgery (MIS) is growing in the field of foot and ankle, and the MIS burr is an emerging tool. Although commonly used to perform osteotomies, the burr can also be used for arthrodesis joint preparation that traditionally would be performed through open incisions. To date, there is no study comparing the quality of joint preparation between using a fluoroscopy-guided MIS technique compared to traditional open techniques. The goal of this cadaveric study is to compare the percentage of joint surfaces prepared between MIS and open techniques for the most common joints that are fused in foot and ankle surgery.

METHODS

Open joint preparation was performed under direct visualization with open incisions. MIS joint preparation was performed percutaneously using fluoroscopic guidance alone, without arthroscopy. After joint preparation, cadaveric samples were disarticulated, and joint surfaces were analyzed for percentage of cartilaginous surface removed. The percentage of joint surface prepared was compared between the open and MIS techniques.

RESULTS

Ten cadaveric samples were used for the MIS technique and 5 samples for the open technique. Percentage of joint surface prepared was similar for all joint surfaces.

CONCLUSION

The MIS technique in the hands of experienced surgeons was found to provide overall similar percentages of surface area prepared compared to traditional open techniques.

CLINICAL RELEVANCE

MIS joint preparation may be useful for specific patient populations. This study suggests that MIS joint preparation is a reasonable, and possibly advantageous, alternative to open preparation in arthrodesis surgery when performed by experienced MIS surgeons.

Mini-open vs. Transfibular Approach for Ankle Arthrodesis, Which Approach is Superior in Joint Preparation: A Cadaver Study

BACKGROUND

Arthrodesis is considered the gold standard for end-stage ankle arthritis in patients who fail conservative management. Achieving union is paramount while minimizing complications. An essential item for successful union is preparation of the articular surface. Our study aims to evaluate the difference in joint preparation between direct lateral and dual mini-open approaches.

MATERIALS AND METHODS

Ten below knee fresh-frozen specimens were used for this study. Five were prepared through lateral approach, and five using dual mini-incisions. After preparation, all ankles were dissected and images of tibial plafond and talar articular surfaces were taken. Surface areas of articulating facets and unprepared cartilage of talus, distal tibia, and distal fibula were measured and analyzed.

RESULTS

A greater amount of total surface area was prepared with the mini-open approach in comparison to the transfibular approach. Percentage of prepared surface area of total articulating surface (including talus and tibia/fibula), talus, tibia, and fibula with the transfibular approach were 76.9%, 77.7%, and 75%, respectively. Percentages were 90.9%, 92.9%, and 88.6% with the mini-open approach. When excluding medial gutter, there was no significant difference between techniques (83.94% vs. 90.85%, p = 0.1412).

CONCLUSION

Joint preparation with the mini-open approach is equally efficacious as the transfibular approach for the tibiotalar joint. The mini-open approach does provide superior preparation of the medial gutter and inferior tibial surface which may help to increase union rates and decreased complications.

LEVEL OF EVIDENCE

V.

Joint Preparation and Ray Shortening in Arthroscopic Versus Open First Metatarsophalangeal Fusion: A Cadaver Study

Purpose This study compares the amount of joint preparation and first ray shortening following first metatarsophalangeal (MTP) joint fusion utilizing open conical reaming versus arthroscopic technique. Methods Ten below-knee cadaver specimens were randomly assigned to undergo either open or arthroscopic first MTP fusion. Following fixation, first ray length measurements were obtained from pre-operative and post-operative radiographs and were used to determine first ray shortening. Additionally, the ratio of first ray length to second ray length was calculated both pre-operatively and post-operatively and compared between the two approaches. All ankles were then completely dissected, and prepared surface areas were demarcated. ImageJ photo analysis software (National Institutes of Health, Bethesda, MD, USA) was used to calculate the percentage of prepared and unprepared cartilage of each articular surface of each specimen.  Results Overall, the open approach resulted in 99.3% ± 1.6% joint surface preparation, whereas the arthroscopic approach yielded 92.9% ± 7.2% (p = 0.089). On average, the head of the first metatarsal was significantly more prepared with the use of the open approach (99.5% ± 1.1%) than with the arthroscopic approach (96.6% ± 1.5%) (p = 0.008). However, with respect to the base of the phalanx, the average difference in preparation between the arthroscopic approach and the open approach was not statistically significant (90.0% ± 12.8% vs. 99.0% ± 2.2%; p = 0.160). The average amount of first ray shortening in the arthroscopic approach was 2.2 ± 1.8 mm compared to 2.1 ± 3.2 mm in the open approach (p = 0.934). The average change in the first to second ray length ratio was 0.02 for both approaches (p = 0.891). Conclusion Arthroscopic first MTP fusion can be used to achieve joint preparation comparable to open technique while maintaining first ray length.