Introduction and Objective. Zone 2 flexor tendon injuries are still one of the challenges for hand surgeons. It is not always possible to achieve perfect results in hand functions after these injuries. There is no consensus in the literature regarding the treatment of zone 2 flexor tendon injuries, tendon repair and surgical technique to be applied to the A2 pulley. The narrow fibro-osseous canal structure in zone 2 can cause adhesions and loss of motion due to the increase in tendon volume due to surgical repair. Different surgical techniques have been defined to prevent this situation. In our study, in the treatment of zone 2 flexor tendon injuries; Among the surgical techniques to be performed in addition to FDP tendon repair; We aimed to compare the biomechanical results of single FDS slip repair, A2 pulley release and two different pulley plasty methods (Kapandji and V-Y pulley plasty). Materials and Methods. In our study, 12 human upper extremity cadavers preserved with modified Larssen solution (MLS) and amputated at the mid ½ level of the arm were used. A total of 36 fingers (second, third and the fourth fingers were used for each cadaver) were divided into four groups and 9 fingers were used for each group. With the finger fully flexed, the FDS and FDP tendons were cut right in the middle of the A2 pulley and repaired with the cruciate four-strand technique. The surgical techniques described above were applied to the groups. Photographs of fingers with different loads (50 – 700 gr) were taken before and after the application. Proximal interphalangeal (PIP) joint angle, PIP joint maximum flexion angle and bowstring distance were measured. The gliding coefficient was calculated by applying the PIP joint angle to the single-phase exponential association equation. Results. Gliding coefficient after repair increased by %21.46 ± 44.41, %62.71 ± 116.9, %26.8 ± 35.35 and %20.39 ± 28.78 in single FDS slip repair, A2 pulley release, V-Y pulley plasty and Kapandji plasty respectively. The gliding coefficient increased significantly in all groups after surgical applications (p<0.05). PIP joint maximum flexion angle decreased by %3.17 ± 7.92, %12.82 ± 10.94, %8.33 ± 3.29 and %7.35 ± 5.02 in single FDS slip repair, A2 pulley release, V-Y pulley plasty and Kapandji plasty respectively. PIP joint maximum flexion angle decreased significantly after surgery in all groups (p<0.05). However, there was no statistically significant difference between surgical techniques for gliding coefficient and PIP joint maximum flexion angle. Bowstring distance between single FDS slip repair, kapandji pulley plasty and V-Y pulley plasty showed no significant difference in most loads (p>0.05). Bowstring distance was significantly increased in the A2 pulley release group compared to the other three groups (p<0.05). Conclusion. Digital motion was negatively affected after flexor tendon repair. Similar results were found in terms of gliding coefficient and maximum flexion angle among different surgical methods. As single FDS slipe repair preserves the anatomical structure of the A2 pulley therefore we prefer it as an ideal method for zone 2 flexor tendon repair. However, resection of FDS slip may jeopardizes nutrition to the flexor digitorum profundus tendon which weakens the repair site. Therefore the results must be confirmed by an in vivo study before a clinical recommendation can be made. Keywords: Flexor tendon; injury; pulley plasty; cadaver;

Extensor tendon attachment to the dorsum of the proximal phalanx may fully extend the finger metacarpal phalangeal joint (MPJ). 15 fresh-frozen cadaveric hands were axially loaded in the line of pull to the extensor digitorum comunis of the index, middle, ring and small finger at the level just proximal to the MPJ. We measured force of extension at the MP joint in 3 groups: 1) native specimen, 2) extensor tendon release at the proximal interphalangeal (PIP) joint with release of lumbricals/lateral bands, 3) extensor tendon release at the PIP joint and dorsal proximal phalanx and lumbrical/lateral band release. Degree change of extension was calculated using arctan function with height change of the distal aspect of the proximal phalanx, and the length of the proximal phalanx. We used Student T-test to determine significant decrease in the extension of the phalanges. Extension of all fingers decreased slightly when the extensor tendon were severed at the PIP joint with release of the lateral bands/lumbricals (8deg+/−2deg). After this release, the finger no longer extended. Slight loss of extension was not statistically significant (p >.05) between group 1 and group 2. Groups 1 and 2 were significantly different compared to group 3. In summary, distal extensor tendon transection and release of lateral bands/lumbricals resulted in little change in force and degree of finger extension. The distal insertion of the extensor, released when exposing the PIP joint dorsally, may not need to be repaired to the base of the middle phalanx

We hypothesized that the finger extensor mechanism has attachments along the dorsal surface of the entire length of the proximal phalanx and that this anatomy has not been clearly defined. The attachment along the dorsal aspect of the proximal phalanx of the index, middle, index and small fingers was dissected in 20 fresh-frozen cadavers. The lateral bands and attachments along the lateral and medial surface were released to appreciate the attachments along the dorsal aspect. We characterized the ligament attachments as very robust, moderately robust, and minimally robust at the distal, middle, and proximal portions. Three orthopaedic surgeons quantified the attachment, finding that 93% of specimens had tendinous attachments and the most robust attachment found at the most proximal and distal aspects adjacent to the articular cartilage. 87% of the specimens had very robust attachments at the proximal portion of the proximal phalanx. The middle portion of the proximal phalanx had moderate to minimally robust attachments. Greatest variability in attachment was found along the most distal portion of proximal phalanx adjacent to the proximal interphalangeal joint (26% of specimens had moderate to minimal robust attachment; 74% had robust attachments). The attachments along the proximal phalanx were attached on the dorsal half of the proximal phalanx, with no fibrous attachments extending past the lateral bands. In summary, we found tendinous attachment along the proximal phalanx that may assist in finger extension and may extend the digit at the metacarpal phalangeal joint without central band contribution

Tenodesis effect and digital cascade of the foot were never described in the current literature. However, understanding of these effects are important in the diagnoses and managements of foot flexor tendon rupture and lesser toe deformities. We aim to investigate the presence of these effects in the foot with intact and cut tendons. Ten fresh frozen cadaveric specimens were used in our study. 2. nd. , 3. rd. and 4. th. toe metatarsophalangeal joint (MTPJ) and proximal interphalangeal joint (PIPJ) range of motion (ROM) at ankle resting position were measured. Same measurements were repeated with maximum ankle plantarflexion and dorsiflexion. 4. th. toe Flexor Digitorum Longus (FDL) was then identified over plantar aspect of metatarsal shaft and cut transversely. 2. nd. , 3. rd. and 4. th. toe MTPJ and PIPJ ROM at ankle resting position, maximum plantarflexion and dorsiflexion were then measured. Mean 4. th. toe MTPJ and PIPJ ROM at ankle dorsiflexion were 13.5 ° of dorsiflexion and 25 ° of plantarflexion respectively, compared with values at ankle plantarflexion which were 35 ° and 25 ° respectively. After 4. th. toe FDL was cut, mean 4. th. toe MTPJ and PIPJ ROM at ankle dorsiflexion were 14 ° and 24 ° respectively and at ankle plantarflexion the values were 34.5 ° and 25 ° respectively. At ankle resting position before 4. th. FDL was cut, mean 4. th. toe MTPJ and PIPJ ROM were 22 ° and 31 ° respectively, compared with the values after 4. th. FDL was cut, ie 22.5 ° and 30.5 ° respectively. Tenodesis effect of the foot was shown in our study. However unlike in hand, this effect was only present in MTPJ and was still present following cut FDL. Similarly, digital cascade was still present following cut FDL. The maintenance of tenodesis effect and digital cascade following cut flexor tendon is likely contributed by various soft tissue restraints and intrinsic muscle actions. These findings are important in both the diagnosis and management of foot flexor tendon rupture and help us to better understand the biomechanics of lesser toe deformities and the managements of these deformities

Objectives

To determine the pattern of mutations of the WISP3 gene in clinically identified progressive pseudorheumatoid dysplasia (PPD) in an Indian population.