However, a party whose negligence causes injury to another is liable only for those damages actually and proximately caused thereby. Haws v. Bullock, 592 S.W.2d 588 (Tenn.Ct.App. 1979). A defendant is not liable for damages from an earlier condition or injury, not having caused those damages, except to the extent of aggravation or enhancement by the defendant's acts.

We note that the first surgery was not performed until May 14, 2001, more than five months after the accident which worsened the knee problem, and absent the exacerbation it is not conclusive under the proof when surgery would be necessitated, merely `sooner or later' according to Dr. Cates. The defendant City correctly argues that it cannot be held liable for Mr. Emert's pre-existing condition, and that a trier of fact must separate pre-existing injuries from the new injury and award damages only for the injury. Baxter v. Vandenheovel, 686 S.W.2d 908, 912 (Tenn.Ct.App. 1985), Haws v. Bullock, 592 S.W.2d 588 (Tenn.Ct.App. 1979). We think the trial judge recognized these legal principles, because he emphasized the exacerbation of the pre-existing problems by the fall which hastened the need for knee replacement surgery, and further recognition is inherent in the disallowance of medical expenses apportioned to the pre-existing condition.

A plaintiff can recover for an increase in disability resulting from an accident , but not for [his] total disability resulting from the pre-existing condition plus the aggravation caused by the accident.McMurry v. Metro. Gov't of Nashville , 2003 WL 535918 at *7 (Tenn. Ct. App. Feb. 26, 2003) (emphasis added) (citing Haws v. Bullock , 592 S.W.2d 588 (Tenn. Ct. App. 1979) and Kincaid v. Lyerla , 680 S.W.2d 471 (Tenn. Ct. App. 1984) ). Accordingly, Dr. Burns' supplemental report need not show that Hudson's pre-existing psychological issues and behavior had "conclusively resolved" before the crash in order for Plaintiffs to collect damages.

However, he is entitled to recover damages for any aggravation of such pre-existing condition or disability proximately resulting from the injury." Haws v. Bullock, 592 S.W.2d 588, 590-591 (Tenn.Ct.App. 1979) (quoting Tennessee Pattern Jury Instruction § 14.08). Further, "[w]here a pre-existing condition or disability is so aggravated, the damages as to such condition or disability are limited to the additional injury or harm caused by the aggravation.

Of the states that have considered this issue, the vast majority have held that if the jury cannot apportion damages between a preexisting and an aggravating injury, the defendant is liable for the total injury. LaMoureaux v. Totem Ocean Trailer Express, Inc., 632 P.2d 539, 545 (Alaska 1981); Newbury v. Vogel, 151 Colo. 520, 379 P.2d 811, 813 (1963); Maser v. Fioretti, 498 So.2d 568, 570 (Fla.Dist.Ct.App. 1986); Bushong v. Kamiah Grain, Inc., 96 Idaho 659, 534 P.2d 1099, 1101 (1975); Lovely v. Allstate Ins. Co., 658 A.2d 1091, 1092 (Me. 1995); McNabb v. Green Real Estate Co., 62 Mich.App. 500, 233 N.W.2d 811, 819-20 (1975), superseded by statute on other grounds, Mich. R. Evid. 404; Brake v. Speed, 605 So.2d 28, 33 (Miss. 1992); David v. DeLeon, 250 Neb. 109, 547 N.W.2d 726, 730 (1996); Kleitz v. Raskin, 103 Nev. 325, 738 P.2d 508, 509 (1987); Pang v. Minch, 53 Ohio St.3d 186, 559 N.E.2d 1313, 1324-25 (1990) (relying on Restatement (Second) of Torts § 433B cmt. d); Haws v. Bullock, 592 S.W.2d 588, 591 (Tenn.Ct.App. 1979); Tingey v. Christensen, 987 P.2d 588, 592 (Utah 1999); Phennah v. Whalen, 28 Wash.App. 19, 621 P.2d 1304, 1309 (1980); Bigley v. Craven, 769 P.2d 892, 898 (Wyo. 1989). Only two states considering the issue of indivisible injury have rejected this approach.

In Kawamoto, doctors had treated the plaintiff for an arthritic neck at least eight years before the defendant aggravated the plaintiff's pre-existing condition in an automobile accident. See, e.g., Bigley v. Craven, 769 P.2d 892, 898 (Wyo. 1989) (cervical degenerative disc disease); McNabb v. Green Real Estate Co., 62 Mich. App. 500, 516, 233 N.W.2d 811, 818-20 (1975) ("brittle diabetic"); Lamoureaux v. Totem Ocean Trailer Exp., Inc., 632 P.2d 539, 542 (Alaska 1981) ("thoracic outlet syndrome"); Haws v. Bullock, 592 S.W.2d 588, 591 (Tenn.App. 1979) (degenerative arthritis and degenerative disc disease in neck and back); see also Damages in Tort Actions § 15.34[1][b] ("[s]hould apportionment of damages prove impossible in a pre-existing condition case, the tortfeasor may be liable for the whole of the plaintiff's injuries.").

As discussed supra, Willis will likely continue to experience set-backs and recurrent symptoms. It is well-settled that a negligent party takes a plaintiff as the defendant finds him or her, and the injured plaintiff is entitled to recover all damages proximately caused by the acts of the responsible party. Haws v. Bullock, 592 S.W.2d 588, 591 (Tenn.Ct.App. 1979); Fuller v. Speight, 571 S.W.2d 840, 841 (Tenn.Ct.App. 1978). Although some individuals might recover quickly from a traumatic experience of this nature, the evidence does not suggest that Willis is among this group.

A defendant is not "responsible for plaintiff's previous condition, except to the extent of aggravation or enhancement by defendants' acts." Haws v. Bullock, 592 S.W 2d 588, 591 (Tenn. Ct. App. 1979). Thus, a plaintiff may recover for an increase in disability, but not for the total disability which resulted from the pre-existing condition plus aggravation of the pre-existing condition caused by the accident.

According to his treating physician, Hunter will experience difficulty performing work that requires certain types of physical exertion, an obvious aspect of the type of employment to which he is best suited, given his mental limitations. It is well-settled that a negligent party takes a plaintiff as the defendant finds him or her, and the injured plaintiff is entitled to recover all damages proximately caused by the acts of the responsible party. Haws v. Bullock, 592 S.W.2d 588, 591 (Tenn. App. 1979); Fuller v. Speight, 571 S.W.2d 840, 841 (Tenn. App. 1978). Here, the defendants' negligent conduct caused significant injury and impairment to an individual who is mentally retarded — one who must rely upon his physical skills for future employment.

The jury, having reached this conclusion, would not be obligated to compensate plaintiffs in this judgment for injuries suffered in both accidents. See Haws v. Bullock, (1979 Tenn. App.E.S.) 592 S.W.2d 588. Furthermore, next to the jury, the Trial Judge was in the best position to determine the reasonableness of the verdict. See Strother v. Lane, (1976 Tenn. App.M.S.) 554 S.W.2d 631. Once the Trial Judge has, as here, approved the verdict, appellate Courts must give great weight to that decision.