The injury was first described almost 80 years ago. The first known repair technique was proposed in 1952 by Paatsama. Since then, many techniques have been described/used. They are generally either intra- or extra-capsular procedures. The former are typified by the under and over technique. Among the latter are the fibular head transposition, tibial plateau leveling osteotomy, tibial tuberosity advancement, and various fabellar suture techniques.
In Practical Repairs of Cranial Cruciate Ligament Tears , Walter Renberg, DVM, MS, DACVS, of Kansas State University, writes: "Some techniques place sutures on both medial and lateral aspects of the joint, and some place sutures through one or two holes in the tibia while others use the patellar tendon. The fibular head transposition (FHT) was introduced in 1985 by Smith with additional publications investigating the procedure published later. Finally, Slocum introduced his cranial wedge osteotomy and later the tibial plateau leveling osteotomy (TPLO). The TPLO was a patented procedure which therefore required surgeons to attend a training course if they desired to perform the surgery. Unfortunately, the course had an excessively long waiting list for most practitioners. This fostered some negative feelings among the veterinary community. Additionally, the expense associated with the course and equipment, and the difficulty of the procedure made it less advisable for many veterinarians. The patent for the procedure has recently expired which may make the procedure more available. Similar procedures include tibial wedge osteotomies and tibial tuberosity advancement."
In his evaluation of advantages/disadvantages, Dr. Renberg adds: "The advantages to intra-articular techniques lie in the fact that they may recreate normal biomechanics better than other procedures and in the observation that the graft will revascularize to resemble ligamentous tissue. The biomechanical advantage has not been shown to correlate with decreased severity of arthritis or with higher performance. Additionally, the various intra-articular techniques are generally somewhat more challenging than a LFS."
Your companion obviously means a great deal to you and I understand that you want only the best for him so I appreciate you asking about this. Perhaps you will want to share this info with your vet. As far as I know, there's no more recent (or more importantly, definitive) studies or findings.