**15. Arthroscopic treatment of thumb carpometacarpal (CMC) osteoarthritis**

Thumb CMC joint pain, instability and progressive arthritis is a common problem affecting many patients, especially middle-aged women. Once present, the symptoms of thumb CMC osteoarthritis are typically progressive and may lead to significant functional disability. There are two classifications for thumb CMC osteoarthritis: Eaton – Litter classification which is based on radiological changes [109] (**Table 7**) and arthroscopic classification developed by [110] (**Table 8**). He also presented an algorithm for management of the CMC osteoarthritis incorporating arthroscopical stages into radiological classification and subsequent treatment decision-making. Treatment methods depend on the stage of the radiologic and arthroscopic findings and can contain detriment, thermal shrinkage, correctional osteotomy of the 1st metacarpal base as well as arthroscopic resection with different interposition arthroplasties or suspensionplasties.


#### **Table 7.**

*Eaton-Litter radiological classification of 1st CMC arthritis.*


#### **Table 8.**

A. Badia *arthroscopic classification of 1st CMC arthritis.*

With recent advances in arthroscopic techniques, partial trapezectomy with or without different soft tissue or implant interposition has been reported with good results [111–114]. Theoretical advantages over open procedures include a decreased risk of neurovascular injuries, smaller incisions decreased postoperative pain and shorter overall recovery time. On the other side, this technique has several disadvantages, including increased setup and operative procedure time,

**Figure 40.**

*(a) preopertive x-ray of 1st CMC arthritis, (b) CMC portals connected with skin incison, (c) Regjoint Scaffold sutured before insertion via elongated CMC portal, (d) Implant pulled in and positioned in the site, (e) transfixation of the bones and implant with K-wire.*

### *Wrist Arthroscopy DOI: http://dx.doi.org/10.5772/intechopen.99191*

increased surgical training, increased equipment cost and additional x-ray fluoroscopy time [115].

There is growing evidence that techniques involving use of no interposition result in a high rate of satisfactory outcomes [116, 117]. Cobb et al. in 2015 compared outcomes of patients treated with or without tendon interposition and found no difference in outcomes.

Another promising technique is an arthroscopic hemitrapeziectomy and suture button suspensionplasty [118, 119].

Authors have their own small experience (6 patients) with arthroscopic hemitrapezectomy and interposition arthroplasty with RegJoint™ implant (**Figure 40a**–**e**). The follow up is 12 to 36 months without any severe complications. Marcuzzi et al. in 2020 published long-term results with open technique [120]. They found dissapointing radiological results with an almost complete collapse of the metacarpal base on the distal pole of scaphoid in more than 80% of patients. However the results did not correspond with clinical outcomes that were very satisfactory. We hope that arthroscopical technique preserving the dorsal capsule will improve the outcomes, but further investigations are necessary.

Complication rate with arthroscopic CMC arthroplasties is about 4% and include as follows: CRPS, ulnar or radial sensory nerve neuropathy, transitory numbness near the portal, prolonged hematoma, FPL tendon rupture and superficial skin necrosis [121].
